This podcast was published in the hottest year on earth in recorded history. What does this mean for child health? How can we as pediatricians help protect the most heat-vulnerable in our communities?
Learning Objectives: By the end of this episode, pediatric residents will be able to…
1) Describe the relationship between rising ambient temperature and its effects on pediatric health
2) Differentiate between mild, moderate, and severe heat-related illness
3) Describe how urban heat islands disproportionately affect areas of lower socioeconomic status
4) Illustrate the growing threat of wildfires in the United States
Hosts
Sophia Gauthier, MD, MSPediatric Hospital Medicine Fellow at Dell Medical School at University of Texas at Austin
Graham Aufricht, MDPediatric Emergency Medicine Fellow at Dell Medical School at the University of Texas at Austin
[00:00:00] Sophia Gauthier: Welcome back to episode two. I am Sophia Gauthier. And I’m Graham Aufricht. We are pediatricians and the hosts of this podcast, Clinicians, Kids, and the Changing Climate.
[00:00:11] Graham Aufricht: All right, Sophia. So what is our topic today?
[00:00:15] Sophia Gauthier: So I am going to counter with what is the largest cause of environmental mortality in the United States?
In kids? In, in, in everybody. Actually, okay, hint, uh, particularly in young children and athletes such as football players, um, those are pretty high risk populations. Okay,
[00:00:34] Graham Aufricht: so we live in Texas, we are recording this in August, and it is well over 100 degrees outside, plus you mentioned football players, and they have a season that, uh, basically begins during the summertime, so I’m gonna go with extreme heat.
Exactly.
[00:00:51] Sophia Gauthier: Extreme heat kills more people than hurricanes, lightning, tornadoes, and floods. Heat waves are becoming longer, more frequent, and more severe over time. So today, we’re going to talk about the global warming aspect of climate change. We’ll start with body physiology in extreme heat, and then we’ll move into the concept of urban heat islands, and then close with some discussion on wildfires.
Okay,
[00:01:16] Graham Aufricht: well, walk me through it.
[00:01:17] Sophia Gauthier: So, first, the impacts of extreme heat start actually in the earliest stages of life. There are associations that exist between extreme heat events and increases in preterm birth and stillbirth. There’s also an association between heatwaves and pediatric emergency room visits, as well as hospitalizations.
[00:01:36] Graham Aufricht: All right. And remind me, why are children particularly vulnerable?
[00:01:40] Sophia Gauthier: So this is kind of interesting. Physiologically, children have immature thermoregulatory ability. They produce more heat per mass. They have a lower body sweat rate. They divert a greater proportion of their cardiac output to the periphery during high temperatures.
And Something that is, I think, most people know, young children also lack the developmental skills, so I’m thinking like really young, like babies, toddlers. Um, they lack the developmental skills necessary for protective behavior modification, like drinking more water, shedding excess clothing, or even leaving a locked car when it’s too hot.
Okay,
[00:02:14] Graham Aufricht: so, children are particularly vulnerable to extreme heat, which is the highest cause of environmental deaths in the U. S. I work in the emergency department. What should I be looking
[00:02:24] Sophia Gauthier: out for? So, heat related illness can be divided into three categories, mild, moderate, which is also known as heat exhaustion, and severe, which is known as heat stroke.
[00:02:34] Graham Aufricht: So mild heat includes things like heat rash, but sometimes we see people have bigger reactions to the heat, such as passing out in really hot environments. That’s usually caused by something called venous pooling.
[00:02:46] Sophia Gauthier: It’s important to note that body temperature remains normal in mild heat illness, so around 37 degrees Celsius.
[00:02:52] Graham Aufricht: This is in contrast to moderate. and severe heat illness.
[00:02:55] Sophia Gauthier: So moderate heat illness, also known as heat exhaustion, occurs when the core body temperature rises between 37 and 40 degrees Celsius because the ambient heat begins to overwhelm your own body’s core thermoregulatory abilities. Symptoms can include dizziness, headache, fatigue, even vital sign abnormalities like tachycardia and tachypnea.
You can see GI upset, even vomiting, diarrhea, and muscle cramping. But there is no central nervous system dysfunction and no end organ damage. Okay,
[00:03:26] Graham Aufricht: so how do we differentiate this from severe heat illness or
[00:03:30] Sophia Gauthier: heat stroke? So heat stroke is the most severe, and these are the cases that you often will see in the news.
Heat stroke can be differentiated from heat exhaustion by two major principles. Number one, in heat stroke, core body temperature will exceed 40 degrees Celsius. And number two, uh, symptoms include end organ damage, which can include CNS dysfunction like delirium or even seizures, as well as cardiac irregularities like arrhythmias, you can see hypotension, even GI bleeding and muscle tetany, and notably the skin can actually be dry instead of sweaty.
[00:04:04] Graham Aufricht: I think this is a huge opportunity to educate coaches and teachers in the community about signs of heat illness and
[00:04:10] Sophia Gauthier: how to treat it. Absolutely. And since you have more experience in a pre hospital setting, what can pediatricians teach coaches and athletes about treating heat exhaustion and heat stroke?
Well,
[00:04:21] Graham Aufricht: in the field, patients should be transferred to shade or cooler environments as soon as possible. As soon as you’re seeing those Early signs that somebody could be getting more hot than they should be. They can be covered in cold, damp, wash cloths, particularly in the groin, in axilla, or immersed in cold water or an ice bath.
Hydration is gonna be key and you can also do some cooling via IV fluids once they get to the healthcare, uh,
[00:04:45] Sophia Gauthier: setting. So now we’ve talked about heat related illness and the way in which children are uniquely vulnerable, but it’s important to note that children in marginalized. communities are also disproportionately vulnerable to extreme
[00:04:58] Graham Aufricht: heat.
So you’re referring to the concept of urban heat islands?
[00:05:02] Sophia Gauthier: Yeah. Like, okay. Imagine a bubble of warm air over a city and urban heat island is a geographically concentrated area where ambient temperature is significantly hotter than surrounding areas on average, up to seven degrees higher. So
[00:05:17] Graham Aufricht: how does that happen exactly?
[00:05:19] Sophia Gauthier: There are kind of several contributing factors. So number one, usually cities have a lack of green spaces. Leaves in trees, they provide shade, but they also store water that can evaporate, which causes air cooling. This is also known as transpiration. Number two, this um, is in contrast with building materials like asphalt, brick, and steel.
All of these things absorb, store, and subsequently emit more solar radiation than natural surfaces. Number three, all those building materials that I mentioned tend to be dark in color and absorb more heat. There’s actually efforts to paint the tops of buildings with white or reflective paint. These have demonstrated to significantly decrease the local ambient temperature.
Number four, in heavily developed areas, buildings obstruct natural wind flow, which disrupts natural cooling mechanisms. And number five, cities are full of… Things like vehicles, HVAC systems, industrial facilities, all of these produce a lot of heat waste.
[00:06:16] Graham Aufricht: Hmm, interesting. Is the urban heat island effect uniform across an individual
[00:06:21] Sophia Gauthier: city?
So interestingly enough, no. The severity of urban heat islands varies within cities, and there have been multiple studies linking neighborhoods that were historically redlined in the 1930s. Thirties, they tend to house low income minority populations with more severe heat islands.
[00:06:37] Graham Aufricht: So does that mean that the greatest risk of heat occurs within cities?
[00:06:42] Sophia Gauthier: Not necessarily. So this actually brings us to our last topic, which is wildfires.
[00:06:47] Graham Aufricht: So this has been in the news pretty frequently this year, both with the Canadian wildfires and the devastating fires in Maui. Can you talk about how climate change contributes to the threat of wildfires? So
[00:06:58] Sophia Gauthier: from a climate perspective, longer dry seasons and shorter winter frost leaves vegetation drier for longer.
The extent of area burned by wildfires annually has been increasing, with peaks coinciding with the hottest years. For example, the Canadian wildfires this year in 2023 were part of the country’s worst wildfire season on record. Substantial greenhouse gas emissions and forest loss from wildfires are likely to accelerate climate change further, possibly lead to kind of a reinforcing feedback loop.
Wildfires not only cause death, property damage and displacement, they lead to mental health challenges, which we will address. later in the podcast, but they also lead to the degradation of ambient air quality, which is what we’re going to focus on in the next episode.
[00:07:43] Graham Aufricht: Okay. So before we close out, let’s talk about some key takeaways from this episode and opportunities for
[00:07:49] Sophia Gauthier: action.
Okay. So first extreme heat is the largest cause of environmental mortality in the United States and it’s increasing in frequency. Second,
[00:07:58] Graham Aufricht: there are three stages of heat related illnesses. Mild. Moderate, a. k. a. heat exhaustion, where core body temperatures rise between 37 and 40 degrees, and severe, a. k. a.
heat stroke, where the core body temperature exceeds 40 degrees and you see signs of CNS dysfunction and end organ damage. Treat with rapid body cooling and hydration, and be active in educating the community.
[00:08:22] Sophia Gauthier: Third, urban heat islands are a measurable example of the disparities that exist between the impacts of climate change on different socioeconomic classes.
This is a great opportunity to advocate for things like medical legal partnerships in our clinical spaces, where we can help communities get affordable access to things like utility assistance or advocate for programs that aim to greenify vulnerable neighborhoods.
[00:08:46] Graham Aufricht: All right, so that wraps up episode two.
Thank you so much for listening. Stay tuned for the next great episode, which will be on air quality and respiratory health. This
[00:08:55] Sophia Gauthier: podcast was researched and written by myself, Dr. Sophia Gauthier. A massive thank you to my friend and co host, Dr. Graham Aufricht. The podcast was produced by the fantastic audio engineers at the University of Texas at Austin Liberal Arts Instructional Technology Services.
Team with funding via a pediatric medical education grant and instructional support from the medical education fellowship at the University of Texas Dell Medical School.