The Invisible Impact: Heat and Children's Health

In this episode, host Stephen Goldsmith speaks with Dr. Lindsey Burghardt, MD, MPH, FAAP, chief science officer at the Center on the Developing Child at Harvard University. Dr. Burghardt discusses the critical intersection of urban heat, health, and equity, particularly focusing on how extreme heat affects prenatal and early childhood development. She emphasizes the importance of place-based decision-making for city officials and how targeted interventions  based on developmental stages can mitigate the adverse impacts of heat on sensitive populations.

Listen here, or wherever you get your podcasts. The following is a transcript of their conversation.

Stephen Goldsmith:

Welcome back. This is Stephen Goldsmith, Professor of Urban Policy at the Bloomberg Center for Cities at Harvard University. Today we have a guest I'm very excited about, Dr. Lindsey Burghardt, who is the Chief Science Officer at the center on the Developing Child at Harvard University. She's the founding director of the center's Early Childhood Scientific Council for Equity and the Environment. We had the privilege of hosting Dr. Burghardt at our recent Urban Heat Resiliency Design Workshop, a lot of words, where she spoke to city leaders about municipal solutions. Happy to have you on the podcast so we can share your insights with our broader audience. Welcome Dr. Burghardt.

Lindsey Burghardt:

Thank you. Thanks Stephen for having me.

Stephen Goldsmith:

So you've done all this stuff and it's all important, but the focus of our conversation today is how city officials should think about heat and health and equity in terms of what they can or should do about it. So your presentation to our group of city officials was one of the most motivating that they have heard in the period of time we've been working with them. We have a grant sponsored, as you know by Robert Wood Johnson Foundation, to look at the use of data in cities in order to improve those pollutants and environmental conditions that affect kids. So lots to ask you about, but maybe before we do that, could you give us a brief background on how you got to where you are and exactly what is your position today as it relates to environment and children's wellbeing?

Lindsey Burghardt:

Yeah, thanks for the question. Besides my science hat that you mentioned, the other hats I wear on the mother of three young kids and I'm also a practicing pediatrician. And after my pediatric training I decided to do a pediatric fellowship and to focus that training in emergency medicine. And that's why I came to Boston originally. And in the ER I learned very firsthand how so many children experience significant adversity in early life illness and injuries that we as a society really have the ability to prevent. So I think if we can change for me the way that we think about caring for children and families and shift this onus of responsibility for children's well-being solely on their caregivers and think more collectively about how we can care for kids, I started to feel like that was really a powerful thing that I wanted to devote my time and energy to.

So I became, as an ER doctor, really interested in how we can leverage public health and leverage policy to really care for children. And it led me to do a master's of public health and health policy. And when I was doing that coursework, I sort of had this major 'aha moment' where I was taking a course between the Ed School and the School of Public Health on early childhood and I learned about this incredibly wide range of influences that there are from our environments on lifelong health that begin even well before we're born. So there's this incredibly robust science base there around the prenatal period, around early childhood. I was learning so much about what happens early in life and how it influences our health and well-being, I had gotten through all of this pediatric training in medical school and this had never really risen to the top.

For me, I hadn't heard about it a lot before, but it was amazing, this sort of untapped potential that I was hearing in the science. And so when I started to really understand about how much our early experiences in our early environment shape our well-being really across our life course, I knew this is where I wanted to focus my efforts and I really wanted to bridge the space between science and policy, which I think is again such an area where if we could make more of these connections, we could really do a lot of good. And it gets into our conversation and understanding that really well before birth kids' development's shaped by this whole range of exposures that they have and all of their experiences that they had in the places where they live. And we call these developmental environments, but these environments shape children's experiences and their exposures and their biological systems again, this is in the prenatal period, are reading constantly the environment and they develop in response to what they read, so.

Stephen Goldsmith:

Well you just said like a hundred important things in the last two paragraphs, so.

Lindsey Burghardt:

Well thank you.

Stephen Goldsmith:

Before you get onto the next issue, let's have a language check here in the following sense. So much of the work we've done has focused on place-based decision-making for cities. So we use a spatial equity map that comes from Esri. It's much more discreet than the Justice40. I mean discreet in the sense it's narrower and you help make decisions in it. You speak in terms of sensitive populations. So just in terms of how we should think about those who a mayor could help, I want to get to in a second to the consequences of heat. But before we get there, should we focus on place? Should we focus on sensitive populations? Just give me a language tutorial please.

Lindsey Burghardt:

I think it all starts from place, right? Because children don't have these exposures that we sort of focus on in a policy realm and isolation. They don't just experience heat. They experience heat in the context of where they live and it's the full sum of those exposures. So when you talk about place and why place really matters, it's because place is really your social relationships, it's your built environment, your natural environment, and the way that those things interact.

So a child who lives in an urban context without access to green space, without access to cooling measures with strong social cohesion will experience heat really differently than a child in a different place who has different developmental environmental exposures. So that's the first factor. But then the way that their biological systems respond to place and to all those experiences and exposures that they have, it actually depends on the point during development that they're in. So everything that happens to us is sort of this combination of our genes, which of course are not our destiny. That's definitive now and it's not all genes and it's not all place, it's both. It's how they interact. And your second point is the timing at which those interactions occur. And I think it's worth delving into that in a little bit more detail.

Stephen Goldsmith:

If we're going to focus on using levers that would help, I'm going to keep coming back to this kind of the levers that a city official has, help the most people the most. Would we focus on sensitive populations in underserved communities, what would you recommend that the focus be children in certain communities that fit the definitions you just mentioned?

Lindsey Burghardt:

Yeah, I think that this is a place where exactly to your point, the science of development. So what we know about development is not only telling us what to do, but it's telling us when to do it to leverage the greatest impact. So it's both. It's looking at children who are living in the places where they're most likely to experience a disproportionate burden of adverse environmental exposures and looking at which, I can tease out a little bit more the point during development when those exposures are most likely to have an effect. So it's not an either or, it's an and factor. And I think it might help to think about development when you break it down to understand why looking early and looking at different sensitive periods will matter because it's not like you can pick one and expect this outcome or pick a different one and expect another outcome.

We're all really sensitive to our environments, but development is a process that's evolving in ways that makes certain age ranges really sensitive to environments. And what this means is that the experiences and exposures that kids have in their environment during this time are going to influence their health in the moment but also later. And so to your point in general, biological systems in children beginning in the prenatal period are developing very rapidly. And the outcome that children will have depends on when they're exposed, including to extreme heat. So in general, sensitivity in the prenatal period is much greater than it is in young children. And young children are much more sensitive in turn to most exposures than older children who are more sensitive than adolescents who are more sensitive than most adults.

And so to your point, looking early at when biological systems are particularly sensitive, is largely going to have an outsized effect on positive outcomes because again, it can affect health in the moment but also across the lifespan. And that's true when we think about kids in general. So many of the most costly and prevalent diseases in adulthood, think about obesity, heart disease, neurodegenerative diseases all have their root very, very early in life. So anything that we do to not protect children during those periods are likely to have an outsized negative effect on outcomes. But the converse of that is if you protect children during pregnancy, you're very likely to reap significant benefits, not only in the moment, but again when they're much, much older when they reach the school system and then in adulthood.

Stephen Goldsmith:

So ever since I heard you speak, I've been calling people shouting what you said, like, "Look what I just heard from Dr. Burghardt. What are you doing about it? Test scores and low birth weight babies and premature birth. So just pretend here for a second. You have 50 city officials in the 50 largest cities in front of you, tell them why they should intervene and for whom's benefit they'll make the most difference."

Lindsey Burghardt:

Well, that's a dream scenario. Let's make that happen. I appreciate that. We're here to talk about heat, right? And normally when you hear about heat in the news or when it's discussed in policy circles, we tend to hear a lot and rightly so about impacts on the elderly and especially those who are isolated and a lot of more general discussions about our population as a whole. And these populations are really important. And again, rightly so, we hear a lot about things like emergency room utilization rates during heat waves because this information can be really accessible and it's really informative and heat stress and heat stroke in adults is really important. But again, there's actually this much earlier and quite invisible way that heat affects a really large number of people living in our cities. And that's the effect of heat on prenatal and early childhood development.

And so these effects are in a couple of big categories for me. It's fetal development and pregnancy learning, sleep and mental and behavioral health. And we can talk about each of these a little bit more, but luckily there are things right now that we can do to keep kids safe from these threats. And there's communities and cities that are implementing them with good effect. So effects on pregnancy first I think are really important to talk about because in times of extreme heat, there's normal changes that happen during pregnancy that actually can create additional risk both for the fetus and for the pregnant person. So bodies already produce more heat during pregnancy because there's more metabolism you need to support fetal development and there's strain from body the mass. And these adaptive measures that happen during pregnancy to compensate for these changes can actually be overwhelmed in times of extreme heat and lead to difficulties.

And so these may be things we're not quite sure how the clinical effects of extreme heat in pregnancy occur, but it's probably through mechanisms like reduced blood flow to the placenta and inflammation. And these things can trigger preterm birth and higher rates of stillbirth and babies that are born too small. And so the evidence is increasingly clear that during times of high temperatures, there's more babies who are born too early and more babies who are born too small for the time in gestation that they're born. And this is really, really, really important for people to understand because when you're born too small or too early, this can raise your risk of dying or becoming ill both immediately when you're born, but also of a range of adverse outcomes later in life, impaired cognition, reduce growth in childhood, cardiovascular disease, diabetes and adulthood. So if we don't take efforts to protect pregnant people from extreme heat, we'll likely see and feel that impact in our hospitals when these babies are born.

But also in our schools, in our adult medical care systems, when these kids grow up and in the U.S., these adverse pregnancy outcomes of being born to early, preterm or early term, we're already looking at probably about 10% of our births. Estimates vary depending on the week that you look of pregnancy, but that's likely 300 to 400,000 babies in the U.S. annually. So if you take a factor like extreme heat, that may increase this outcome even a little bit, this could have just huge implications for public health, both immediately but also in the future, again, when these babies reach the schools and when they reach adulthood. And so by protecting pregnant people and making sure more babies get off to a healthy start, we're actually improving all these downstream effects that I think are really underappreciated in our current discussions around the effects of heat.

Stephen Goldsmith:

Babies born in extreme heat. I understand what you've said and just so important, but you also mentioned cognitive performance. I think you're talking about for children, infants born in heat, but I heard you say that extreme heat can affect test scores, cognitive performance in school. So just before we move to what cities should do about this, this is a huge factor. Tell us a little bit about that. Would you please?

Lindsey Burghardt:

Yeah. And heat and learning are actually, I think closely tied for me to sleep and mental health, which are the other effects on heat. So when you think about one effects on learning, I think it's really important to realize how interconnected those effects are. So heat probably leads to learning losses because it slows our cognitive function and it reduces our ability to concentrate. You can imagine this conversation would be a lot less interesting and engaging if it was a hundred degrees in the room where you were sitting. And this is another one of these invisible effects, right? It causes slow reaction times, it's hard to focus. And we need to think about teachers here too. So if you're learning in a hot classroom, students are going to feel unmotivated and distracted, but so are their teachers.

And it's reasonable when we're thinking about schools here to think about these school-age kids. But this also is very transferable to our youngest learners kids in early care and education settings, infants who learn and who have this brain development through play. And so if schools are uncomfortably hot, they can be forced to close early or for days at a time. And we saw this last year, right in the United States, even in places that are typically really cool, Philadelphia, Michigan, Massachusetts, we had schools that had to close for days at a time because classrooms were too hot. And the good news is that cooling mitigates to a large degree, these effects. For the average student school air conditioning appears to offset about 73% of the learning impact of hot school days. The statistic that I love that you mentioned earlier, student performance can be expected to increase on average by 20% if classroom temperatures are lowered from 86 degrees Fahrenheit air temperature to 68 degrees, which is pretty amazing.

And then sleep ties in here, right? Because sleep is a pillar of health. And normally actually when we fall asleep, our core body temperature drops and that actually helps us to fall asleep. But if it's really hot where you're living and a lot of communities don't have that drop in temperature at night, it's harder to fall asleep and for children that is critically tied to their learning. So even if we're cooling classrooms, which is wonderful and important, if they're not cool at home where they sleep and where infants nap, that really is going to affect their mental health, their behavior, and their sleep the next day in school.

Stephen Goldsmith:

We talked at the meeting you attended through the day about intervention strategies, shade and air conditioning and different building materials and street materials, a range of issues that city officials had control over. To your earlier comments and effort to kind of look at sensitive populations and target interventions there but many of the cities have great difficulty getting anonymized public health data. How would you recommend really sophisticated data capacity in your city? How do you get that data to identify where to make the greatest investments, the most important investments?

Lindsey Burghardt:

Yeah, I think it's a really difficult issue because as you mentioned, when it comes to identifying and reaching populations, pregnant individuals, young children, a lot of the more general census-type data that public health departments can access may not be sufficient and you may not have that level of detail that you need, but a lot of times that important data is in the hands of the healthcare facilities, but it's not easily shared because of HIPAA and other constraints as you mentioned. And so I think thinking about partnering and working with people in academics could be a really powerful way to start thinking about beyond emergency room rates, how many people are being admitted to our NICUs, and what are the rates of people being admitted to maternity wards for preterm labor? Because that data is, again, it's these invisible effects of heat that aren't being measured, but the hospitals have more access to that data.

And I think academics and people in research are particularly interested in making that information actionable. And I think that the next most important thing is thinking about working with community-level organization partners because they know their neighbors and they have the trust of those neighbors and can play a role in facilitating conversations. But again, in many conversations about heat, not all, but many, I think we think about general populations and in the general population, pregnant individuals and young children right now are not even being named, often, not always as groups that we need to think about having community members engaged with. And so if we can bring pediatricians, pediatric healthcare practitioners, parents into those conversations, I think direct engagement actually with community partners can be a really valuable way of identifying in the spaces in the city that are the hottest and we're starting to understand where those are can be a really powerful way of reaching people and understanding context-specific heat. Because again, the way that one neighborhood experiences heat and the solutions that they have at hand, even within the same city may be really different than in other neighborhoods.

Stephen Goldsmith:

So let's assume that you have access to the data, you overlay the hospital information with built environment information, heat island identification. What would you recommend a city do to mitigate those consequences?

Lindsey Burghardt:

I think it's helpful when we think about addressing extreme heat, other climate-related impacts, to think about acting on three levels, protecting, adapting, and preventing. So when we think about protection and what city level officials can do to help protect kids from extreme heat, these are things like taking immediate action to reduce harm when there's extreme heat events or heat waves. And this can look like partnering with medical teams and clinics that serve the most sensitive populations. And when they provide prenatal care, engaging people at their prenatal visits to sign up for the text alert systems that many cities have now about extreme heat events, and then talking with them or providing resources or where they can go to learn about what they can do at an individual level when these extreme heat events occur to help them stay safe. There's also cities like New York has a cooling assistance benefit now to help eligible households to buy and install air conditioners or fans.

And the qualifications include you need to have a letter from a healthcare provider, but having a medical condition that's exacerbated by extreme heat or having a child under the age of six in the home. So making sure that healthcare providers and pediatricians have that information because people often vary consistently as a group access healthcare and prenatal care in particular as places that they go consistently throughout their lives. Second, if we want to think about adaptation and adapting, it looks like how do we change our current systems and services and infrastructure to acknowledge the fact that temperatures are going to stay high? And I think this is where the learning comes in with community members and leaders about where pregnant people in urban heat islands in particular are spending time and targeting resources. This gets back to your first question to cooling these places. So learning where young infants are spending time and how if we have resources to update infrastructure for air conditioning or heat pumps and if those funds exist, targeting them to the places that people are most likely to access.

And then while we're working to make these bigger system improvements that can take more time, there are some cost-effective things that we could do today. So painting roofs with white paint and cooling buildings by putting shade structures next to them can be very cost-effective. Again, thinking about where are the buildings and where are the places where pregnant people and young children are spending time? It's difficult sometimes for early care and education settings because in many cities there's not one unified network of early care and education. So thinking about how do you make sure that non-traditional settings, whether they're in-home, daycares or smaller facilities also have access to these resources. But when you do something like put a shade structure next to a building, you can lower the temperature inside the building, but you're also having this huge co-benefit because then you're creating a cool outside place for children to spend time, which is so important for them, for their mental health, for their physical health.

And then we have to think about on this third level of preventing and addressing the root cause of why cities are warming so rapidly. And that means thinking about how we can decrease our dependence on fossil fuels. And there's an example from Boston, Boston Medical Center Hospital in our city, as you likely know, that predominantly serves underserved communities, including low-income families. For many of their patients, they found that paying utility bills to keep their homes cool in the warm weather months was really a challenge. So they leveraged federal and state incentives for BMC's clean power prescription plan, and it lets their providers actually write a prescription for reduced energy bill using renewable energy.

So the hospital installed solar panels and they redistribute the solar energy credits from BMC's power grid to their patients. So the patients actually get monthly credits to their energy bill of about $50 a month or $600 a year, which in Boston is about 30% of many people's energy costs. And then the hospitals encouraging other businesses and real estate holders and institutions in the area to also donate their energy credits to these lower income communities. And then this lets the program provide short-term support to caregivers and kids in Boston while the community leaders and researchers and government officials are sort of looking and exploring these more long-term options that take a little bit more time to get into place.

Stephen Goldsmith:

That was a really exciting answer.

Lindsey Burghardt:

Thank you.

Stephen Goldsmith:

I never heard of that program. I'm going to go find out about that. That's really clever. I have one more question for you, and you may have a couple other points you want to make, but I always worry about messaging because in these circumstances there is a tendency, it feels to me like to blame the victim. That is to say, well, since I've created this environment in which you live where you have so much heat, now here's what you need do to fix it, right? So acknowledging that a city should do all the things you just said for the first two thirds of our conversation, what would the message be to sensitive populations or parents in these circumstances? What should we be telling them so that they can take some action to help mitigate the problem?

Lindsey Burghardt:

Yeah, first I think cities are already creating a lot of fantastic messaging guides, but again, the messages are often really targeted towards the elderly and older people. So I think acknowledging how difficult it is to be a caregiver or a pregnant person in times of extreme heat and naming that we see that you are a population that is going to have particularly big challenges in this group, I think that that's huge. I also think that among my patients in particular, many people appreciate actually more often than not understanding what heat actually does from a health perspective. Because I think to your point, they're told over and over again, it's a problem. It's a problem, but connecting and understanding how it can affect health can be really empowering. So for example, I would say most of my patients are surprised to learn that heat can worsen their child's asthma.

And so helping to explain and help them to find resources in the city for cooling or cool places where they can go, can be very empowering to say, "Here's something that you can do to prevent the effects of heat from worsening your child's asthma." And then to your point, I think it's really important that when we go and say over and over and over again that this is a neighborhood that's an urban heat island, you're going to have more heat than other people to pair that messaging with solutions on the individual level. So there are things that people can do tomorrow if it's too hot in Boston, but also it's a place where we need to step in and empower people on collective caregiving that actually it's our responsibility and our ability as citizens of our society to take care of all kids and to enact and create policies and empower communities to push for these policies that actually drive systems level change.

And I think that encouraging policy makers to work across sectors and to have cross sector conversations about these issues are key because again, it's going to help to highlight and bring in groups that are currently being left out of the conversation. And one thing I would add to that, so Boston for example, Boston has a work group that's made up of representatives from over a dozen city departments and programs that are working on different aspects of climate change, and they meet regularly and keep one another up to date. And it allows for this cross pollination across departments and sectors, both for ideas and opportunities to collaborate and to support one another. And I think that that's a really important point in the success for messaging as well.

Stephen Goldsmith:

So if our goal is to help the greatest number of children in large U.S. cities who are suffering the consequences of heat, what is the one thing I haven't asked you that you would recommend that city officials do?

Lindsey Burghardt:

I don't know. You asked some good questions. The one thing that I'd say that I do think is really important for listeners and that just I would really love to communicate to policymakers who are listening is that even though we're talking about heat today, there's sort of similar situations that are happening and conversations that are happening in multiple other policy domains where there's often really large and often invisible impacts of our decisions and our policies and the problems that are facing people and their impacts on pregnant people and young children. And again, there's implications for each of these conversations for health in the moment, but some of the effects that I think you and maybe others are struck by on what it means over a child's life course.

And so whether we're talking about urban planning, water safety, air quality, minimum wage laws, zoning laws, all of these things have similar and yet invisible effects on really big numbers of children. And so I would really love to call for a shift in our thinking about how as citizens we can kind of collectively provide caregiving for children by designing policies that protect them and set this lifelong trajectory for health and wellness. And again, one way to do this might be bringing in pediatrics and bringing in parents to some of these policy conversations, even if it's something like a zoning law that might seem at the surface not to affect kids at all, because it really profoundly does, and we love to help make those connections.

Stephen Goldsmith:

Well, let me just say that was the best answer for a person who didn't have an answer to a question, I think I've heard. So this is Steve Goldsmith, Professor of Urban Policy at the Bloomberg Center at Harvard University, with just a terrific conversation today with Dr. Lindsey Burghardt, who is the Chief Science Officer at the center on the Developing Child at Harvard University. Lindsey , thank you so much for your time and your insights today.

Lindsey Burghardt:

Yeah, thanks for having me, Steve.