Austin doctor speaks on signs, symptoms of heat stroke and exhaustion

AUSTIN, Texas - June 20 was the official first day of summer, but Central Texas has been feeling the heat for a while now, and we have a long way to go before temperatures cool off. 

In the first week of June alone, Austin-Travis County EMS reported 48 heat-related calls when Texas had heat indices in the triple digits. 

Dr. Ryan McCorkle, an emergency room physician with St. David's Medical Center, joined FOX 7 Austin's Rebecca Thomas to discuss.

REBECCA: So we've had a hot May, a hot June. We're looking at triple digit heat indices next week. How busy have you been in terms of dealing with heat-related illnesses?

DR. MCCORKLE: We've definitely seen an increase in the volume of heat-related complaints coming in to the emergency department at St. David's. Ranging from heat exhaustion all the way to more cases of heat stroke this year than we've seen in recent years.

REBECCA: And, let's talk about the differences between, for example, heat exhaustion and heat stroke.

DR. MCCORKLE: Heat exhaustion is where people are starting to adapt to the heat that is being overcome. They're beginning to get lightheaded, sometimes lose consciousness. Go from sweating profusely to not sweating as much. And that's where you start to move from heat exhaustion into heat stroke. When they stop sweating and become altered, they can get some swelling of the brain called cerebral edema, and become altered, lose consciousness. And that's when we call it heat stroke.

REBECCA: How dangerous is heat stroke? What does it actually do to the body?

DR. MCCORKLE: Heat stroke is where the brain actually starts to swell. You can have permanent damage. We've had several cases where we've had to put people on a ventilator. And use the invasive cooling measures where we run chilled IV fluids into their veins, put a catheter into their bladder and run chilled fluid through that. And then the misters, is really the evaporative cooling, is how we rapidly reduce people's core body temperature when they have heat stroke.

REBECCA: Now, Central Texas is a very active outdoors community. People like to exercise and hit the trails even in summer. What advice do you have for people to do this safely during the hotter months?

DR. MCCORKLE: As physicians were always happy to see people being active. It's great for our overall health, but during these times of the year, it's so important. If you're going to be active, you need to do it in the early morning hours preferably, or the very late evening hours, talking before eight in the morning after 8 p.m. Those peak hours, especially in the afternoon, are just that's how you're going to end up in the ER with me, is being out during that time of day trying to exert yourself.

REBECCA: I know hydration is also key. How much water should men and women be drinking? And kids, of course, too.

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DR. MCCORKLE: Sure. We, like, we say, for females to be somewhere around two liters, a little bit more, depending on your body mass. But that's kind of a good starting point. If you're heavier than that, a little more, if you're less than that, a little less. Kids, their body temperature regulation is not mature yet, so they have a harder time adjusting to the heat. So they need to be hydrating, make sure they have good consistent urine output. And they're not getting overheated. See that change in the color of their skin or starting to get lethargic or sleepy.

REBECCA: And, I know they say by the time you're thirsty, you're already dehydrated. So talk about the importance of hydrating before working out.

DR. MCCORKLE: You have to pre-hydrate in this heat and with this humidity. You've got to start before you even head out. It's not enough to just take fluids with you. You should be drinking several hours before you're planning on having activity. You may even want to consider things like Pedialyte or a sports drink mixed with water to get some electrolytes, too. There are rare cases where people drink way too much, just water, and decrease their body sodium and have problems from that. So we do like to see people mix in some electrolytes in addition to drinking just water.

REBECCA: So if you experience symptoms of a heat related illness, or you see someone out and about in distress, what actions should you take to potentially save a life?

DR. MCCORKLE: So if you see something, we want to get any restrictive clothing off. The biggest thing that really helps is the evaporative cooling. So you see restaurants and things have those misters on the outdoor patios. That's actually good evidence based things. If you have, we use spray bottles in the ER to spray people down so they can get that evaporative cooling. That's what sweating does for you. But once we've outstripped our body's ability to keep up by sweating, putting that cold mist on people will really help decrease their core body temperature rapidly. But get them to drink if you can, get them into a shaded area and that mist if you can get a hold of it.

REBECCA: All right. Dr. Ryan McCorkle with St. David's Medical Center, thank you so much for sharing your time and expertise with us.