Venita (Host): This is UAMS Health Talk. How's the weather today? If it's hot, do you know how to protect yourself from heat-related illnesses? With me today is Dr. Ashley Norse from the University of Arkansas for Medical Sciences. She's an expert in heat-related illnesses, and she's got some great advice for us to keep us safe this summer. Thank you for joining us, Dr. Norse.

Ashley Norse, MD: Thanks for having me.

Host: I am surprised to hear that there are different types of heat-related illnesses. Can you first explain what is heat-related illness, and then describe what are the different types of heat-related illnesses?

Ashley Norse, MD: Well, there's a spectrum of heat-related illnesses that range anywhere from a rash or heat exhaustion or muscle cramps, all the way to heat stroke. And so, the symptoms are different and varied for different patients. But the entities are some patients will be out in the heat and they'll break out in what's called a heat rash, which is red, itchy bumps usually in the torso area.

Kind of the next level are patients losing a lot of fluids and electrolytes, and they develop muscle cramps. And then, you move into heat exhaustion. And that's where you'll see a varied range of symptoms from headache, nausea, vomiting, dizziness, sweating, to you can even see people pass out, what we call heat syncope. And then, the final and worst obviously entity of heat illness is heat stroke. And this is where you'll start to see people present with slurred speech. They lose consciousness. They have a very fast heart rate. They may be sweating, or the converse may be true and they may have stopped sweating. They may have very hot, dry skin. But a whole range of signs and symptoms for heat-related illness.

Host: I wonder as someone is maybe outdoor exercising, running, when I see people out running in heat, I get really nervous for them. What are some signs that we should be checking in on our bodies that maybe we need to stop and take a break if we're exercising outdoors?

Ashley Norse, MD: So, the first thing I would say is if you're exercising outdoors, don't do it in the heat of the day. That's one of the things with heat-related illnesses is if you can avoid being out in the hot heat, intense part of the day, you should. So if you're going to do cardio-intensive outside exercises, try to do them in the morning or evening when it's a little bit cooler and the sun is not as intense.

But also, one of the big factors in developing a heat-related illness, especially if people are going to be active, is have they acclimatize to it? So, you'll see my son plays Football. they do early morning practices, late morning practices, but they acclimate to the heat. And that's a big factor. If people are not used to it, they run a higher risk of developing a heat-related illness. And then, also the extremes of age, they're very young, the older people. And then, people with comorbid diseases like diabetes, cancer, things like that run a higher risk of developing heat-related illness.

But to answer your question, if you're out doing exercise in the heat of the day, the big thing is you want to make sure you're well-hydrated because not being well-hydrated is going to lend you to having heat-related illness because the way the body cools itself is you sweat and your vessels dilate, you sweat more to try to lower your body temperature. And so if you're not well-hydrated, when you start exercising out in the summer heat that we're experiencing right now, you're going to run the risk of developing heat-related illness.

The other thing is making sure you're wearing sun-protective clothes, but clothes that breathe. So light colored clothes, clothes that breathe. This is hard for some of our workers who are out there and have to have protective gear on that predisposes them to heat-related illness because they've got this protective gear, they've got dark clothes. But wearing light clothes that are made for the sun that are breathable, acclimating yourself to the heat, being well-hydrated are going to be things that are going to help you kind of avoid developing heat illnesses.

Host: When you talk about acclimating to the heat, what does that look like? Does that mean like doing a certain exercise for 10 minutes then 20 minutes? Like, what does acclimation look like?

Ashley Norse, MD: Doing the exercise for shorter periods of time and building up, but then also building up to doing it in the times of the day that are not as hot. If you've got to do something at noon, between noon and two o'clock in the day, three o'clock in the day, don't just go out there and do it for the first time. You have to build up to that. So, your body's used to it.

Host: And another thing that you mentioned is that the older we get, the more we need to take care of our bodies. So, are there specific groups of people who are more likely to be in distress in hot weather?

Ashley Norse, MD: Children, younger children, their bodies are different. And so, they are predisposed to dehydration. They have a higher chance of developing a heat-related illness. And then, the converse in the elderly population, same is true.

And so, those populations, if you're out doing stuff this summer, you need to make sure, again, you're staying well-hydrated, you're taking frequent breaks, preferably going indoors into an air conditioned area. But if that's not possible, at least the shade, frequent breaks, frequent hydration, making sure you're really paying attention to those signs and symptoms that children and elderly that may be out with you or not developing heat-related illness.

Host: I've been doing these shows for a while now, and it just amazes me how beautifully made our bodies are, but we need certain things to function properly. Can you just explain to us the mechanics that happen when we find ourselves in distress because of a heat-related illness?

Ashley Norse, MD: So, like I said, the way the body compensates is your vessels dilate. And so, you have more blood flow going closer to the skin. You're going to sweat more. As you sweat and you're losing fluids, remember, sweat also carries electrolytes like salt chloride and things like that. And so, as your body is trying to cool itself, the vessels are dilating, it's bringing the blood flow closer to the skin surface so you can sweat more. You're going to lose fluids, you're going to lose electrolytes. And then, kind of the way the body cools itself is as the sweat hits the skin surface and the wind blows across it, it kind of cools the body down. And so if you're in a place where there's no breeze, there's no wind, it affects that mechanism. But eventually, if you're not staying hydrated, your body loses that ability to regulate itself by sweating, because now you're dehydrated and you can't compensate by lowering your body temperature by sweating and cooling itself. And so, that's when you kind of run into that heat-related illness.

One of the things that you will see as you start to become dehydrated, your heart rate picks up because you're losing fluids. The way the body compensates for that is your heart starts working harder to try to move the fluids that are still in your body, the blood volume that's still there around. And so, your heart rate speeds up and causes a fast heart rate. So, one of the first signs you'll see, you may start feeling bad, feeling dizzy, nauseated, having a headache, but the other sign that you'll see is your heart rate will go up.

Host: So for someone who may be seeing this happening to a loved one or a friend or someone on the street, is there anything that we can do to help them through this moment of crisis?

Ashley Norse, MD: Yeah. So if it's one of the less severe illnesses on the spectrum, the muscle cramps or the heat exhaustion, fluids, fluids, fluids, fluids. And people think water. But keep in mind, as you're sweating and losing fluids, you're also losing those vital salts and electrolytes. And so, once somebody starts to have these muscle cramps and heat exhaustion, think about some of the sports drinks as well that have the electrolytes in it so that in addition to replacing the fluids, you're replacing the electrolyte. But get them fluids and getting them to, again, a shaded space or a space indoors with air conditioned to try to cool them off and bring that body temperature back down are going to be imperative to reversing what's going on. So with the muscle cramps, you definitely need to replace electrolytes as well as fluid.

 The rest of the heat illnesses you need to be hydrating. If you can get electrolyte replacement fluids, then do that, but you got to cool the body down. If you can't get them indoors where it's air conditioned and really cool them off a wet rag, a cool compress. In worst case scenarios, we say put some ice under the armpits and the groin around the neck. That blood circulates to try to cool the core body temperature down. Those sorts of things help.

Host: What about for people who are on medication or have a preexisting condition, what should they be keeping in mind as they try to enjoy the summer and be outdoors?

Ashley Norse, MD: Certain preexisting conditions and medications predispose you, again, to heat illnesses, especially any medication that's in the diuretic family. Because again, if you're on a diuretic, part of the way that drug works is you lose more fluids than somebody who's not on a diuretic. And so, drugs in that classes will predispose you to heat illnesses. So, you just have to be cognizant of it. And again, it's the same warning signs. Are you feeling bad? Are you feeling weak? Are you having muscle cramps? Are you feeling nausea? Are you feeling dizzy? Is your heart rate going up? But it's going to be the same to protect yourself. Make sure you're not going out in the heat of the day. Go earlier in the day, go later in the day. Make sure you're taking frequent breaks, you're hydrating, you are getting in the shade frequently. How to avoid it is the same, but you have to know that if you have certain conditions and you're on certain medications, diuretics being the one that pops into mind the most, it will predispose you to maybe more easily developing a heat-related illness.

 I didn't say this because it's not directly related to heat-related illnesses, but make sure if you're outside you wear sunscreen, because that is a whole 'nother protective layer for a whole host of other entities. So, wear your sunscreen when you're outside. Make sure you sunscreen your kids, so that you're not getting burned and you're not predisposing them to skin cancer later on. So, stay safe this summer.

Host: Well, thank you for helping us make smarter choices in hot weather. That was Dr. Ashley Norse. For more information, go to uams.edu. If you enjoyed this podcast or you found it helpful, please share it on your social media channels and check out the entire podcast library for other topics of interest to you. This is UAMS Health Talk. Thanks for listening.