The Brain Architects Podcast: Extreme Heat & Early Childhood Development: A Discussion on Rising Temperatures and Strategies for Supporting Development and Lifelong Health

In April 2024, we hosted a webinar where we explored the science from our latest working paper, Extreme Heat Affects Early Childhood Development and Health. The Center’s Chief Science Officer, Dr. Lindsey Burghardt, joined by Dr. Kari Nadeau, Chair of the Department of Environmental Health at Harvard’s T.H. Chan School of Public Health, brought the latest research and insights from the field to discuss the intersection of heat, early childhood development, and health equity. They also discussed actionable solutions to benefit children, caregivers, and communities now and in the future.  The webinar discussion has been adapted for this episode of the Brain Architects podcast.


Lindsey Burghardt
Lindsey Burghardt, MD, MPH, FAAP
Chief Science Officer, Center on the Developing Child at Harvard University
Kari Nadeau
Kari Nadeau, MD, PhD
Chair of the Department of Environmental Health, Harvard’s T.H. Chan School of Public Health
Rebecca Hansen
Rebecca Hansen, MFA  (Webinar Host)
Director of Communications, Center on the Developing Child at Harvard University
Cameron Seymour-Hawkins
Cameron Seymour-Hawkins (Podcast Host)
Communications Coordinator, Center on the Developing Child at Harvard University

Additional Resources


Cameron Seymour-Hawkins: Welcome to The Brain Architects, a podcast from the Center on the Developing Child at Harvard University. I’m Cameron Seymour-Hawkins, the Center’s Communications Coordinator. OurCenter believes that advances in the science of child development provide a powerful source of new ideas that can improve outcomes for children and their caregivers. By sharing the latest science from the field, we hope to help you make that science actionable and apply it in your work in ways that can increase your impact.  

In April, we hosted a webinar where we explored the science from our latest working paper, Extreme Heat Affects Early Childhood Development and Health. 

The Center’s Chief Science Officer, Dr. Lindsey Burghardt, joined by Dr. Kari Nadeau, Chair of the Department of Environmental Health at Harvard’s T.H. Chan School of Public Health, brought the latest research and insights from the field to discuss the intersection of heat, early childhood development, and health equity. They also discussed actionable solutions to benefit children, caregivers, and communities now and in the future. 

We’re excited to share this conversation on today’s episode of the Brain Architects.  

Now, without further ado, here’s Rebecca Hansen, the Center’s Director of Communications, who will set the stage for our conversation. 

Rebecca Hansen: Hello, everyone, and welcome. We’re very happy to have you all with us for today’s webinar, Extreme Heat and Early Childhood Development: A discussion on rising temperatures and strategies for supporting development and lifelong health. Whether you’re joining us for the first time or have been a regular at our webinars here at the Center on the Developing Child, we are very happy to have you with us today. 

So, today’s webinar is grounded in the first working paper from the Early Childhood Scientific Council on Equity and the Environment. The council is a multidisciplinary group that synthesizes and communicates about emerging science that can help to improve our understanding of how influences from the broader environment affect early childhood development and also lifelong health. The council’s first working paper, published earlier this year, focuses on the many ways that heat can affect development, including its impact on young children’s biological systems and how it can amplify the effects of systemic inequities. 

The paper offers strategies to mitigate the impact of extreme temperatures and points toward actionable solutions for cooling the communities where children live, grow, learn, and play. And we look forward to diving into these strategies throughout today’s conversation.  

So, without further ado, I am going to introduce our panel, starting with a note that while we had hoped to be joined today by Dr. Gaurab Basu, he was unfortunately unable to be here. We do have with us Dr. Lindsey Burghardt, who is Chief Science Officer at the Center on the Developing Child, where she develops and leads the center scientific agenda. She is also founding director of the Early Childhood Scientific Council for Equity and the Environment and leads their efforts to synthesize and communicate about the scientific mechanisms related to how children’s environments shape their development. Dr. Burghardt engages regularly with diverse stakeholders and audiences, with the aim of making the science both accessible and actionable. She is also a practicing primary care pediatrician in the community outside of Boston. 

Dr. Burghardt is joined today by Dr. Kari Nadeau, who is chair of the Department of Environmental Health, and John Rock, professor of climate and population studies at the Harvard T.H. Chan School of Public Health. Dr. Nadeau is a practicing clinician specializing in allergy, asthma and immunology in children and adults, and she has published over 400 papers, many in the field of climate change and health, for more than 30 years. She has devoted herself to understanding how environmental and genetic factors affect the risk of developing allergies and asthma, especially wildfire induced air pollution. Her laboratory has been studying air pollution and wildfire effects on children and adults, including wildland firefighters. Dr. Nadeau is also a member of the Early Childhood Scientific Council on Equity and the Environment. And we are very happy to have her here with us today. 

And with that, I will turn it over to Dr. Burghardt to begin our discussion.  

Lindsey Burghardt: Thanks, Rebecca. I’m so excited for this conversation today. Thrilled to have Kari here with us. I’m just going to start by setting the stage a little bit for why this feels like such a timely and important conversation. And then we’ll dive right in. You know, I think many of us have recognized from our own experiences that temperatures are rising around the world. And, you know, science is confirming we’re having record setting heatwaves that are happening more often and they’re lasting longer than they have ever before. So I think with these increasing temperatures and with the increased frequency of these events, it makes this topic really timely and important because it’s something that’s already affecting kids and their caregivers today. And we know that excessive heat impacts kids development, both in the moment, but also potentially across their lifespan. And the good news is that there’s a lot of solutions that already exist and that communities are putting into effect already with really good results. So we’re going to talk today about how extreme heat affects development, the potential effects in pregnancy and throughout early childhood, and then get into some of those actionable solutions and thinking about how heat works to affect development. We really know that it starts with an understanding that environment influenced all children’s development by shaping the exposures and the experiences that they have. And this developmental environment is really the full range of exposures and experiences that they have in places where they live and learn and play and grow. And so what’s surrounding children is quite literally shaping their biology. But importantly, you know, these experiences and exposures can be positive or they can be negative. So environments can have exposures and experiences that fuel positive development, things like really strong foundational relationships with their caregivers and access to green space and breathing clean air. Or they can be more negative or potentially derail development. So things like extreme heat or breathing toxic air from wildfire smoke. 

So climate change is coming in and it’s creating and shaping changes to this environment of exposures and experiences. And it’s really important to understand, too, that these effects are not only direct on their biology, like breathing in their toxic wildfire smoke, but they’re also indirect and that things like extreme weather events and flooding can cause displacement that then places enormous stress on caregivers, which then has an important effect on those foundational relationships. And when it comes to climate change, this is just the first in a series of conversation that we’re hoping to have about how climate change is shaping developmental environments. And today we’re going to talk about Heat and, Kari, it’s just so amazing and special to have you join this conversation as just really an expert and really thoughtful thought leader in this space. So thank you.  

Kari Nadeau: Thank you. I’m so excited to be here. I’m a pediatrician. I’m a parent. I’ve lived and dealt with heat stress myself as well as climate change. So I’m really happy to be here. As the department chair of Environmental Health, we work a lot with climate change in the global environment, and so our health is inextricably related to earth cell and we need to really focus on early development of children. 

And today, I’ll talk a little bit about how heat, specifically heat stress affects children, because now with climate change here on our planet, every child born today will suffer from at least one severe weather condition associate of climate change and most likely that will be heat. You, I’m sure, all heard on the news that last summer was the hottest summer on record for our earth and unfortunate it will likely be the coolest summer on record for our in the future. 

So we not only have to talk about solutions today, but we absolutely must talk about how those solutions affect children and pregnant women and how it affects the early development of the child. So I’m excited, Lindsey, for your wonderful seminar today and happy to answer any questions from you as well as from the audience at the end.  

Lindsey Burghardt: Yeah, Thanks, Kari. And actually, I am going to hopefully intersperse. We’ve got so many amazing questions that really helped to guide how we shaped the discussion today. And one question that I get a lot that came up quite frequently from the audience when it comes to heat is what do we mean? Like when we say extreme heat or excessive heat, What does that mean? How are people thinking about definitions and how do we kind of start from a common understanding?  

Kari Nadeau: Yeah, that’s a great question. So when we talk about heat, especially in babies that tend to have a lot of extra tissue around, especially with children who are moving around and toddlers who are on the move, typically what we call heat that could affect them physically, mentally, in a in a way that’s not good for their bodies is 85 degrees Fahrenheit. So that’s what people think above, which if you’re exercising and moving a lot, it can actually be a problem for your health. So 85 degrees Fahrenheit is really where we keep the thresholds.  

Lindsey Burghardt: Yeah, that’s super helpful. And I think, you know, the next question that usually follows is what about places where it’s been warm for quite a while? You know, how do we think about heat differently? You know, if you’re somebody listening in from someplace like Boston, that’s typically more cool and dry. How do we think about Heat and children’s the way that they’re going to experience is increasing temperatures differently or the same as a child who has always lived or whose family has always lived in a place that it’s typically more humid or hot.

Kari Nadeau: Right. So as we all know, we grow up in areas of the world with certain cultural habits. And we also make sure that our children are part of those cultural habits as a family. And those are good things. We’re part of that overall environment to take care of the next generation. And with that, for example, in Boston, we tend to have colder weather in New England. 

But the problem with 85 degrees is if it’s in April versus July, where we’re prepared in July to have warmer weather, people already have their clothes out, their shorts are bathing, suits have pools open. But in April, not so much in the middle of Boston. And so people are used to having colder weather. So therefore, they’re going to dress their children and dress themselves up with warmer type layers of clothing and so that’s a problem because part of dealing with heat physiologically is to evaporate our sweat. 

And if we can’t evaporate our sweat, especially for babies and toddlers, because they’re not just little adults, they have different ways of evaporating from their skin because they don’t have as much skin surface area. So it’s actually more dangerous for children not to be prepared for these high temperatures in areas of the world that they’re not used to. 

That, for example, in Switzerland, there were places in the Alps that had absolutely no air conditioning ever. They just didn’t have it because they never thought they need it. And two years ago, they had summer conditions of greater than 100 degrees Fahrenheit and people were not ready. So the children had terrible heat, stress and exhaustion just because people aren’t ready. 

And so we need to when you think about preparing the rest of the world, you’re right. There are places in the global majority and near the equator that are used to heat, but they’ve already adopted the methods to be able to deal with heat that I’ll talk about later on today, because those are methods that have been central to the ecological knowledge of that community that now we have to be humble and listen to so that we ourselves can take the same steps to protect our children.    

Lindsey Burghardt: And that makes so much sense too. And thinking about like, you know, we’re used to something in July that we’re not prepared for in April or even in October. And I think in Boston in particular, we experienced this when it came to our schools and our early care and education settings, which by design were made to keep heat in, you know, and are not adapted then to kind of handle those higher temperatures at times of the year where children are more accustomed to spending time inside. 

So I’m excited to get into that, you know, a little bit later on. So can you talk about, you know, under the skin, how does our body respond, you know, when temperatures increase and how is that different? How is the response different? As you mentioned, it really young children, especially infants who have different physiology.  

Kari Nadeau: Yeah. So on one side, when we deal with stressors, our body handles stress in some similar ways. 

So there’s just a certain pathway that when we deal with early life stressors, it’s similar with heat. There are and pathways that are very similar to other stress pathways. So what I like to think about is these types of life stressors that affect children, especially early on. So and the reason we know so much of this biology is because unfortunately animals out in animal husbandry and agriculture have dealt a lot with heat stress and so have their babies. 

And so we know a lot about mammals and how babies have to deal with heat stress. And so biologically, what will happen, especially even after three exposures of heat waves of 85 to 100 degrees Fahrenheit, where you’re dealing with overheating for more than two days in a row. With that in mind, we’ve seen that these proteins called heat shock proteins, can get activated. 

And the reason I don’t want you all to have to know the molecular mechanisms here, but the important thing is this it’s real, it’s documented. We’ve documented in animals, we’ve documented it in human babies. Key proteins get activated. And why is that important? Because these are stress or proteins that are meant to keep everything stable, to keep everything happy in our blood. 

The minute that they get stressed, the minute that the heat goes up, then unfortunately, they start to activate a pathway that inflames our body. And inflammation is not good. I hope that none of you have to suffer through inflammation, but it can result in disease, it can result in autoimmunity, it results in allergies, it can result in gut problems and skin problems. 

So when our immune system is not happy, it’s not good for a baby, good for a toddler. It’s also the heat itself. Those heat shock proteins are in the brain, so they can also affect cognition and mental health. So unfortunately, our human body is not meant for high amounts of heat. And you could say, well, we learned that the human body stays at an equal temperature and that when we have a fever, we have heat.  

And when children have a fever, they deal with high amounts of heat. That’s true, but it’s not continual. It’s not for five days constantly, for example. And if you don’t hydrate, if you don’t have opportunities to try to decrease that heat, that’s what can lead to trouble. And what we’re finding is that that can be irreversible in babies and toddlers because they’re so sensitive to heat  

Lindsey Burghardt: And those huge shock proteins themselves to have important functions. 

Right. Like they protect your hemoglobin, like other things that are really important in making your other body systems again. And so it’s sort of this really interconnected series of effects, it seems like.  

Kari Nadeau: Yeah, that’s right. So these heat shock proteins are kind of nannies and caretakers for other things in your blood and kind of they’re patrolling the universe to make sure everything else stays really stable and the proteins don’t turn into denatured proteins. 

And what why do I say denatured? Well, if everyone has basically cooked an egg or made egg whites into a whip, they know that if you whip things up, that egg white can actually turn into a foam. And that’s what I mean. If you heat up the human body too much, especially in children, your other proteins start to turn into foam and that’s not good. 

So these heat shock proteins are meant to take care of that. And when they’re disrupted, when they’re too hot, they can’t. So it leads to big problems.  

Lindsey Burghardt: And it’s amazing that we understand that cellular level, you know, where when we think about heat, especially in these sensitive groups thinking about even before birth. Right. What are the effects of heat on pregnancy and pregnancy outcomes Because those of us who think about young children, you know, think about how early brain development really starts and how we can both understand the impacts and then think about protecting groups that might be especially sensitive to heat. 

Kari Nadeau: Yeah, let’s talk about that. That’s really important because as we think about the ways that heat affects infants, toddlers, early development, it really does start a lot of the times in utero. And looking at maternal health is critical. When a woman is pregnant, her heat exchange is different. And for us that remember being pregnant, you get hot much faster because your metabolism is higher.  

You’re pumping out much more blood than another typical person that’s not pregnant. And you’re also carrying a lot more weight. And so that’s hard to release heat as well as other people that aren’t pregnant. And you’re also taking care of another, you know, sort of whole organism. And so with that, in mind, people that are pregnant have much more sensitivities to heat. 

So when I talk 85 degrees Fahrenheit, we actually don’t know the threshold for pregnant women. But we do know that pregnant women are exposed to heat waves, for example, a hundred degrees more than three days in a row. And if they haven’t been given or afforded the ability to get inside, to hydrate, to be in cool rooms, that can lead to prematurity of the child, that can lead to, unfortunately, sometimes premature deaths of the baby and can lead to health issues of the mother herself. 

So with blood pressure changes and other aspects to her health, that needs to be taken care of right away. So heat has a direct effect on pregnant women. And importantly, we don’t know enough about how that affects the child that’s born after delivery. And so people are watching that. And we’re following a group now, for example, in the Central Valley in California. 

But it is important to follow because we need to see to what extent that heat effect and as a woman who’s pregnant affects also her child.  

Lindsey Burghardt: And I think, you know, many people may be familiar with this idea of heat stress or heat stroke in older people or in, you know, children who are athletes. And we kind of can conceptualize that. But there’s also really important effects of heat on our youngest children in terms of their behavior and sleep and their learning. Can you speak a little bit to that?  

Kari Nadeau: Sure. It’s really important to know that our bodies were really meant to be at around 75 degrees Fahrenheit outside. We might be 98.6 degrees Fahrenheit inside our body, but that’s not what we like outside. 

And so especially children, you know, they can get cranky. Adults sleep so well, it’s really hard because they’re metabolizing so fast. Infants also have that nice layer of fat. Typically, it’s hard for them to go to sleep and it’s hard for them to stay asleep because they’re constantly trying to cool themselves. So it’s really important to develop methods by which to make it more comfortable for early child development as well as infants and babies and toddlers. 

So with that in mind, knowing that that age group is much more sensitive, there’s a lot of downstream issues that happen. If you’re cranky, if you can’t eat as well, you’re just don’t feel hungry. You also don’t want to play outside as much. Those are types of interactions that are really important for the cognitive development of any child in early development. 

The other problem is that we know that in early child development, every degree Fahrenheit increase on the outside environment can actually lead to a 1% decrease in test scores. Now, we’re not scoring the average toddler. We know that in terms of tests, but it’s important to know that it affects the brain and affects how the brain is going to function. 

And so, again, our body is not meant to be in greater areas than 75 degrees Fahrenheit to optimally. We don’t want to have to work in that type of temperature or develop in that type of temperature that’s higher than that. And when it does get higher, our brain literally does not function as well. And we have data on that for children. 

Lindsey Burghardt: And I think, too, as a mother, I can remember having three small children and how sort of my own behavior and ability to regulate my own emotions changes in a room that’s, you know, 98 degrees and humid and how that affects the foundation. Our relationship, when I show up for those young children, you know, it’s stress on me that translates to my ability to be present and provide the things that are so important for child development.  

And I’ve learned, too, that. Is it true that, you know, we all of us need a subtle drop in temperature to facilitate sleep onset? And so for you and when we don’t have that, you know, you mentioned trouble falling asleep and having more frequent waking is true of children. And then also the adults who are having more disrupted sleep who can then, you know, be available in a really different way the next day, you know, feels important.  And we think about, you know, oh, sorry, go ahead.  

Kari Nadeau: Now, you’re absolutely right. We’re trying to create the best environments, indirect and directly for our children. And adults don’t get good sleep, which oftentimes happens when it’s hot. You’re right. We use just the lower temperature to be able to just fall asleep for any of us on this earth. 

But I do worry about this because indirectly, heat and living in high areas where there might be violence, the violence actually increases outside and inside the household. And children, unfortunately, are sometimes the victims of this violence or see it, and it’s very stressful to them. So it affects how we behave as adults and it also affects some other behaviors that are irreversibly damaging to children.   

Lindsey Burghardt: And I think, you know, so many of the what we know about how heat changes behavior and leads to increase and in different types of violence, as you mentioned, is getting more measured and available in adults. I think it’s more difficult to measure. I think we haven’t yet, but it would be really interesting to understand how heat really affects the behavior of toddlers and young children, because I think it makes sense that their ability to regulate their own emotions is going to be maybe even more sensitive than ours.  

And we know that this is something that’s affecting adults. So we can only assume that it’s going to affect kids, you know, as much, if not more. And, you know, our conversations about sleep and behavior got me thinking about like where children spend a lot of their time. And I think in particular, many infants spend much of their sleep time and they’re you know, they’re early learning time in early care and education settings, including those that happen in in-home settings.  

So how do you think about what we need to be thinking about in terms of adapting to increasing temperatures both indoors and outdoors when it comes to those particular settings?  

Kari Nadeau: Yeah, I think so many of our children, especially if they’re in nursery schools or in daycare settings, we need to make sure that on the whole we can create better structures to deal with this heat all throughout the world in the U.S.. 

So let’s talk about that because that’s important. We talked about climate change. We’ve talked about heat stress. There are ways to mitigate and adapt to climate change that include biodiversity, vacation, that have fantastic acts, children and how they’re growing. So part of those solutions in daycare centers, in schools, at our own homes can include bio vacation, could include green and real green. 

And the reason that’s important is because part of the simple ways to help decrease heat exposure is to offer shade. So let’s just talk about what are some of the really typical things that one can use practically at home or at a nursery school or at a daycare center to just help to reduce heat? Number one, if it’s going to be hot outside, please make sure you monitor the NOA Web site websites that we can provide you links for. 

There are also provided, I believe, Wendy, in the report, the report from the star. The developing child is fantastic, by the way, and I hope everyone will read it because it offers such great resources to citizens. And I’m really proud of it because there’s so much science in it that can really be tangibly used right now in real time. 

So what does this mean? Let’s talk about solutions on the individual level for heat. First, go to shade. If you’re outside, seek a shaded place. If you’re inside, make sure that it’s shady, not in some sun exposed area. Seconds If there’s no air conditioner, there’s no central air feature that can cool the room, then get a fan, get a bowl of ice underneath that fan. 

And that can reduce the temperatures up to five degrees Fahrenheit quickly in any given room. And so those are some low cost ways to really make sure that you can introduce a cooling system into an area, especially with children running around that want to play, that want to be interactive. The other thing is to get cool, wash clothes and make sure that any skin exposed take away as much clothes as you can, but just cool off the skin because that’ll help it evaporate. 

Better humidity can also reduce the likelihood of evaporation, so anything that we can do to decrease humidity is good. So. So getting that skin cool will allow it to evaporate more as well. And then finally, making sure that the children are hydrated, the babies are hydrated and the people taking care of them are hydrated. So all of these things are simple, easy steps to do. 

The first step, though, is monitor and monitor. Well, now, most cities, most places around our country, at least in the U.S. and many places around the world, have alert systems to let you know if there’s going to be a heat wave. And that’s important because then we can start getting ready. And so I give a list of things to prepare for on the individual basis. 

But these are things that can also be done on the public scale to scale it up across any given area that’s affected by a heat wave.  

Lindsey Burghardt: And I love the fan and bowl of ice tip. I can just like picture and almost feel how that will cool a room and it’s something that, you know, is potentially accessible to a lot of people. 

Now. We’ve been learning a lot and I think there’s a big range of programs that are doing some incredible work. You know, places like the NC State Designs Natural Learning Initiative that are thinking about how to bring greenspace and outdoor environments to children for a number of reasons. And you and I have had conversations before, and I would love to kind of talk about it here about how these natural learning environments, particularly with really young children in these early care and education settings, have such cobenefits, both when it comes to our biology, sort of what happens underneath the skin and then what happens in a range of benefits for children’s development and learning and kind of social emotional health. So can you speak a little bit to those? And also the benefits that it has in terms of lowering temperature because it’s one of these when you start listing off all the great things that this does, it really just seems like a win win win win.  

Kari Nadeau: It really is. And in all humility, we’re learning a lot more about the winds that seem to be exponential in value, especially to young children. 

So let’s talk about that more. So then it’s important for the audience to know that a lot of people now are studying this concept of natural outdoor exposures, especially in children. And there’s a whole sort of system now, both adults and children called natural capital, the investment that we take in nature and how we can get exposed to it more purposefully so that we can help ourselves. 

It also decreases heat when we’re in nature with trees and of course plants themselves. They can emit carbon, but they also sequester carbon. So there’s a lot of things about plants. Let’s talk first about the good things for our brain with plants and with greenery. So we know that one of the great benefits of being outdoors not on a screen that shows outdoors, actually being outdoors and walking and making mental pictures and photographs, wonderful things outside with our children and being able to make sure even in infants to get outdoors and inhale and be part of nature, that really helps cognitive development. 

There are many studies now to show that that helps stimulate your brain. Children do better overall in tests once they get exposed to the outdoors, even for an hour in between recess, they go outside, get exposed to green, not cement tops, but green. In the case of this study that was done in Australia where children in nursery schools got exposed to green during an hour after during their school recess. 

And they actually did better coming back in with such a similar controlled study. So with all that in mind, green is good for the brain, especially infants and developing bright green is also good for tactile learning. And when people have done studies on nursery schools that have green grass and dirt compared to a typical playground, that does not that just has rubberized mats, the children that are exposed to the dirt and play around in the grass, that only do they learn more and they’re more academically aware of things later in life. 

But in addition, they get microbiome, they get good bacteria established in their gut that actually helps their immune system. So a study was done in Finland compared to a controlled group with all other measures controlled for, and they found that the children that were playing more in the dirt were exposed to grass and trees, that they had a different microbiome system in their gut and that that actually helped their immune system. 

And they had and that was measured by how well they responded to vaccines. So this is really important. This is a win win, win, win win cognitive development, tactile development, good microbiome in the gut, good immune system, and then good protection against infections.  

Lindsey Burghardt: Yeah, and it’s lowering temperatures at the same time. It’s amazing. And I love this space because it really feels like a place or whether you’re in philanthropy or policy or already in an early caring education setting like that feels like that’s something that we can do to kind of bring all of these cobenefits into these settings. So it feels like a real place for hope.  

Kari Nadeau: Absolutely it is. It’s I am very hopeful and there are many more people doing work on here with rewilding environments, making sure that in that process of greening we green schools and green nursery schools first, that we prioritize that because we know how important that is for developing children.  

Lindsey Burghardt: And so when we start to think about how we target some of these investments or our attention to make sure that we’re, you know, creating the greatest benefits for children, you know, through, you know, things that you’ve taught me and other members of the council are really kind of built in understanding that heat is not affecting all groups of children equally. And really, there’s so many factors like your socio economic status, your nutrition, living conditions, where you live geographically, what your stages in development. You know, these things all shape the way that children experience heat and the types of heat that a types of effects that he can have on their development. So can you talk a little bit about how heat, you know, sort of amplifies some of these other more systemic inequities and how heat, these effects of heat can be compounded in areas where air quality may already be more of a challenge? 

Kari Nadeau: Right. I’m really glad that at the Center for the Developing Child, you know, you brought us all together in a council to talk about these difficult things and they’re complex, but that doesn’t mean we should step away from them. It means we need to really focus in and understand them better, understand how to prioritize solutions and I’m glad that your center you’ve exactly done that. 

And so kudos to you for being able to have a webinar like this and being able to have systematic ways to approach difficult conversations. And one thing that we’re learning with climate change is it’s really been the x ray and to our soul of health inequities extra into the soul of a lot of communities, especially those including children of color, those including children that get displaced to do climate change. 

We have over 200 million people displaced every year to climate change associated events, and about a 90% of those displaced are women and children. So we need to think about how this affects children on the long term scale and specifically heat, because it is so directly related to climate change. But like you said, when you have heat and you’re already incredibly exposed to things like air pollution, if you live in a community of color, unfortunately, you’re going to have a higher risk as a child to being exposed to toxins. 

And that’s unfortunate because of something called red zoning and redlining that were part of our real estate practices. Now they’re not. But still we have communities that are highly exposed, inequitable. And so what happens is if you have heat stress, if you’re already exposed to air pollution or toxic chemicals, which happens a lot in our underserved, marginalized communities, people of color, people that necessarily have been discriminated against in our country and traditionally, unfortunately, Native Americans and original peoples across the world, those children really have some of the worst statistics for being able to deal with heat because they have underlying issues. 

And unfortunately, we also have an issue around nutrition and good nutrition practices. And for many communities where they might not have access to healthy food, there’s a lot of obesity and that very much affects how people respond, especially children, to heat stress. So with all of that in mind, we need to really think about the most vulnerable, the most and actively exposed, because if we can’t help them as children, as toddlers, as babies, then who are we as a society? 

Because it’s those children we should be focusing on first because they are going to need the most help. And so a lot of work is being done. And so I’m hopeful that the your report is coming out. You talk about these and exposed children and some of these vulnerable communities that we really need to make sure we understand and understand the multiplying effect of these exposures over time, not only in any given day could a child be exposed to heat, air pollution, drought, perhaps a vector borne disease or an under stress event in it for their mental health? 

But in addition, it compounds over the course, like you said, over time. So they have a higher chance of having these issues. But I’m hopeful that their solutions now the EPA is putting out heat risk indices for children, especially those in what we call these communities that are in exposed environmental justice communities. Also, the CDC has a new heat, red heat risk index. 

So you can go online as members of the public, search the Internet and go to the EPA, your Center for the Developing Child report, as well as the CDC, the center basically the Center for Disease Control. And of those information packets, you’re going to find a lot about heat stress and how to help communities. And I’m really grateful that our government has this systematic ways to help the public now. 

Lindsey Burghardt: Yeah, it’s really amazing. I think the amount of attention that this topic is getting and how children are being brought into the conversation. I think even a couple of years ago there maybe weren’t this type of robust, you know, sources of information that they say with heat. And now I think the EPA resources and thank you for the kind words about our report, but just kind of getting these this information out to people who are taking care of young children everyday feels really important.  

And I sort of have heard you kind of draw out our top name almost like three real levels of solutions, right? Sort of like we need to take some immediate actions to keep people safe when these heat waves happen. And but we also need to think about how are we adapting our systems, our services, our infrastructure, Because as you said, you know, this was the coolest summer and that we’ll see going forward. 

So how do we, you know, adapt to that new reality? But then also, you know, and it got to this, I think, a little bit when it came to the early care and education settings, like how do we stop the reasons why the planet is warming so much in the first place by decreasing our reliance on fossil fuels and, you know, decrease our greenhouse gas emissions. 

So, you know, thinking about those three levels of solutions, is there anything that you’ve learned from your work with workers in California or in other places about how we can think about solutions, particularly in urban heat islands where temperatures are much higher? And can we think about applying those solutions to children and to pregnant individuals?   

Kari Nadeau: Yeah, I think there are a lot of solutions now and I’m really grateful. 

So when we talk think about climate change, so many of our solutions have immediate effects on heat, and that’s great because we want to stop warming our planet. It’s not good. We see so many issues around that warming of the planet with drought, with wildfire smokes, with water insecurity, with food insecurity. Heat plants don’t like heat either. Yeah. 

So we want to make sure we think about the whole Earth. This whole concept of one health, planetary health, animals, plants, everything. Heat especially affects them. And so there are ways to adapt to heat, like I talked about with on the individual levels, but on the on the other levels of adaptation and planting more tree canopy, for example, in cities, the urban heat islands are real. 

Many people feel that when they’re in the inner city, Chicago or in a city Harlem or inner city, New York City, they’re going to have degrees up to five degrees Fahrenheit, more in some of the heat islands compared to, let’s say, rural areas. So that’s real. And so what’s happening now is people are realizing, again, thanks to that whole concept of natural capital, planting trees in cities, especially, and children are going to basically benefit from these tree planting exercises, plant trees up to increasing tree canopy by 30%, decreases premature deaths by 30%.  

That’s incredible. And it reduces temperature by 1.3 degrees Fahrenheit. That’s great. That’s substantial. That helps maintain good health, that decreases the risks of heat stress and heat stroke for not just children, but also for everyone. So and that’s a 30% canopy increase. Could you imagine? 50%. So and then the trees will also help absorb carbon. And the most important thing for those of you have allergies to trees. 

It’s actually not going to increase allergies. And that’s also if you plant mixed sex trees, you reduce allergies. And so it’s very cool that we see so many benefits of these systematic ways that cities and communities can actually push for these policy changes. They are happening around the country. In front of you on the phone, please talk to your town councils about increasing tree canopy and plant in the right trees. 

And I’m happy to help in any way. I’ve done a lot of work with different towns and planting trees. The other thing that people are doing more and more is actually using cooling paint. So if you use white paint on roofs or even green roofing, having natural roofs like grass and other things that are happening more in cities like Paris or just planting sort of spruce up, that’s done very much in certain cultures that white roofs and sod roofs, solar panels also reflect light so that that rooftop does not absorb light. 

So solar panels, white roofs, green, real green grass streams, for example, they all help a lot reduce the absorption of that heat. And then there’s new technologies coming out for cooling sidewalks. We’re doing that in Springfield, Massachusetts, for example. Now, there’s also examples of cooling pumps that you can install into your home and you don’t need to leave the home. 

These are low cost methods. And importantly, is talked to your local council, talk to your state, because nowadays states actually give subsidies for air conditioning, for cooling pumps, for offering access to cooling rooms, for example. I know that’s maybe not as easy as having cooling places in your own backyard or your own home, but there are no public cooling rooms available, especially in areas of the country that deal with heat stress. 

And then finally, public places are being offered as ways to cool, cool areas. Now, we are still missing a lot for schools. We need to do a lot more directed work for public schools and private schools for children and nursery school. So I think when we wrote our EPA report for the Children’s Protection Committee, we did say we have to systematically make sure that on the public side that we reduce temperatures in these key areas that are taking care of children. 

So We’re on the road to these types of practices. But I’m really glad to see a lot of cities starting to adopt them now.  

Lindsey Burghardt: Yeah, You talked a little bit about heat pumps. So if somebody is new to the concept of a heat pump, can you explain a little bit about kind of what that looks like, why it may or may not have advantages over air conditioning and then for both of those technologies, you know, one thing that people ask me about a lot is, you know, we have this very old building.  It’s it would take a lot of investment to think about. You know, the EPA, I know, has done a lot of thinking about cost effectiveness and what that actually means in terms of investment versus benefits. Can you speak to that at all?  

Kari Nadeau: Yeah, I’m not a heat pump expert. I mean, people think heat pump, they’re like, oh, well, you’re making heat for me. 

That’s true. The same pump in the wintertime can make heat for you. In the summertime can make cool. So it’s I call it a pump and so they can install this in homes. I’ve seen them they are at the current time they can be very energy efficient so they don’t take as much energy as let’s, say, an air conditioner, which is good because we want to decrease the use of greenhouse gas energy components, increase the ability to use renewable energies and heating pumps are one of those systematic ways of being able to adapt to more renewable energy devices. 

So overall, what, for example the city of Boston is doing, as well as other cities around the country, as well as communities, not just cities. They’re looking at these pumps because they’re more energy efficient. You can install them into your home now without a lot of issues and without disrupting normal living. And they don’t require as much energy, let’s say, as air conditioners do, because people probably no air conditioners use some toxins that then get emitted into the environment and they’re actually really bad for greenhouse gases. 

And so we want to make sure that the very same solutions that we’re using for cooling do not turn into solutions that actually turn out to be worse for our environment and can start to increase change. So that’s where the pumps are actually really helpful. But if you have any other suggestions.  

Lindsey Burghardt: No, no, no. I found it like so amazing when I first learned about it, because you hear a pump and you sort of think that it’s going to like, I don’t know, work off of some type of, you know, coolant like the air conditioners do. 

But they actually in the winter, it’s kind of amazing dry heat out of the air even when temperatures are well below zero. I think the state of Maine has done this at scale and they actually warm many environments, you know, much more evenly in the traditional cooling methods. And then at the same time, you know, they’re able to draw in the summer months that energy and that heat out of the air and actually put it back into the earth in a way that it’s also, you know, cooling to the to the degree of air conditioning is without those negative effects of the greenhouse gas emissions. 

I think, you know, many times when we learn that air conditioning may actually not be great for the environment, but, you know, if you had the ability to put some type of air conditioning in a place where children sleep or where children live and you can lower that temperature, I think we’ve learned that the effects on learning actually are really important when you lower those temperatures and that there’s significant costs associated with the learning losses in the days lost in school.  

And that actually even though you have to invest it, put that money into air conditioning, you’re sort of regaining, you know, the losses that would have happened in so many other ways because of heat. And I think when it comes to young children, especially that ability to like, play and explore and just be curious and be able to move around your environment comfortably is so intangible and hard to measure. 

But thinking about how to get these technologies into places where young children spend time feels, you know, so important. So I love that you Yeah. I mean, it’s great just to think about that. There’s solutions at so many levels that really, no matter where we sit, you know, we have to, you know, we can start to think about, you know, what we can do to make these make environments more comfortable for kids. 

So, you know, if you had to think about if you were working in an early parent education setting, if you were in a school, you know, we’ve talked about a couple of different temperature numbers and ranges today. Is there you could wave a magic wand and say, I would love for these little infants to be able to play and live and sleep at this temperature in these toddlers. Is there a range that you think is helpful for the audience to know about?  

Kari Nadeau: I think 70 to 75 is helpful. I think that that gives us leeway. But, you know, that’s where we’re coming down now. But obviously we want to know what’s harmful so that we don’t get to those temperatures. And that’s like 85 and above and all of this comes conditionally with making sure you’re hydrated, making sure that there’s humanity and dryness differences.  

So with all that in mind, though, Lindsey, it is so important to try to be that change. Now with this information. I hope that your audience will take it forward on the individual level, but also to knock on the doors of your town council, to knock on the doors of your local government and say, hey, you know, can you give subsidies or cooling pumps for certain neighborhoods? 

Can you make sure that they’re in schools? Can you make sure that we deal with good aeration? You know, just a little bit of wind will help with evaporation and will help reduce temperature a lot. So I hope that all of these things that we’ve talked about today will be helpful to your audience. But it’s important that we as a community really advocate for children, for infants, for toddlers, because we as adults, I think that is our a privilege to be able to make sure that we can take care of everyone on this planet, especially those that are early in life. 

Lindsey Burghardt: Yeah thank you. And I learned so much every time I have a conversation with you about this. I wish that I could be like taking notes and talking so I can go back and learn more about all these great things. Is there anything that you would give us sort of a take away or, you know, a final recommendation for people who really want to bring this home? 

I love the thought about coming to your lawmakers, coming to your local government. Is there anything that you would put forward as, you know, something that gets you up and into this work every day with hope and forward looking?  

Kari Nadeau: Yeah. Thank you so much and thanks for everyone for joining. I am very hopeful that we can, through bio diversification, through getting access to more natural environments, actually help our children, especially in early development. 

And I also am very hopeful that because there’s areas of the world that are dealing with extreme heat greater than 40 degrees centigrade, greater than 110 degrees Fahrenheit, this is happening more and more in the news. These are areas that I really do hope we can also think about. How are those children affected and what access can we make sure immediately we can provide to them for healthier lives. 

Lindsey Burghardt: Yeah. Thank you, Kari. This is terrific. We’re so grateful for your time and your expertise and for everything that you’ve taught us today. So I’m going to turn it back over to our host. And thank you all for joining us. We hope to see you again at a future conversation.  

Kari Nadeau: Thank you, Lindsey.  

Rebecca Hansen: All right. Thank you so much, Dr. Burghardt and Dr. Nadeau for this wonderful conversation today. 

I also just wanted to quickly note that we have several additional webinars in development for later this spring and summer where we’ll talk more about different aspects of the developmental environment and other topics related to early childhood development. So please be sure to follow us on social media and subscribe to our newsletter to receive updates and find registration information. 

We’re so grateful to have you with us and we hope you enjoy the rest of your day. 

Cameron Seymour-Hawkins: The Brain Architects is a product of the Center on the Developing Child at Harvard University. You can find us at developingchild.harvard.edu, where we’ll post any resources that were discussed in this episode. We’re also on Twitter @HarvardCenter, Facebook at Center Developing Child, and Instagram @DevelopingChildHarvard. Our music is Brain Power by Mela Collective.  

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