And again, it's an honor to be here on behalf of AMSSM, and I'm just praying my lecture works here. We were working it. I'm going to be talking about exertional heat illness. Again, as was mentioned, I do work for the Department of Defense, and any opinion I'm going to be giving today is my own. It should not be construed as that of the Department of Defense. Otherwise, I have nothing to disclose. So common case for us. You got a 25-year-old male, he collapses at the finish line of the Marine Corps Marathon just down the road in Arlington. He has severe central nervous system dysfunction. He's disoriented. He's dizzy. Irrational behavior, becoming psychotic. And the real questions are, what is the optimal pre-hospital management that you need to be aware of if you're covering this event? And then finally, if he's your patient, when can he resume running? So we're quickly going to be talking a little about the epidemiology that we see in the Department of Defense. I'm going to relate some of the civilian epidemiology, and we'll discuss strategies that you should be aware of for pre-hospital care, the chain of survival, as Dr. Flanagan talked about, return to play, and finally, some resources that you should have at this point in time. So exertional heat stroke. And this is really one of the most common methods that's used across the country in professional and collegiate athletics is cold water immersion in a deep water tub. You can see a rectal thermistor attached right there. I'm going to show you several different methods throughout this lecture. So it's a big deal for us in the military. This is the MSMR. This is the Medical Surveillance Monthly Reports. Every April, we get an index on how many heat strokes there have been and how many rhabdo events there have been in April in the antecedent year. Common problem, but the boys tend to have more heat strokes than the girls. Girls tend to be smarter. Tends to be in the young. Those are the people that we put at risk. Interestingly enough, in the military, year after year after year, Asian Pacific Islanders have a higher risk for heat stroke than other ethnicities. And again, it tends to be recruits who, again, have the higher load. We have between 450 to 500 heat strokes a year in the military. We have about 2,500 heat exhaustions or casualties. It's again, it's a big deal and we do everything to mitigate it, but we have a tough time, as you know, with the heat loads and then the fitness of American youth. But it's a big problem for all of you who are not in the military as well. It's just one article taking a look at exertional heat stroke in football players, which is where it occurs. And this looked at about a 20-year period. There were 54 football player fatalities during these seasons here. You see the majority of them were in high school, but you've got some collegiate and professional deaths as well. I'm going to draw your attention here to this bullet, widely distributed geographically. Doesn't have to be necessarily Florida or Nebraska, occurs in August. We're on the verge of it here shortly with the NFL preseason starting and high school football right around the corner. One-third occurred more than two hours into the practice session. If you take a look at EHI rates across the country in high school, 11 times that of all other sports combined. It's football. It's American football. Casey just talked about a lot of deaths that are very difficult to prevent because they may be congenital, like hypertrophic cardiomyopathy, but arguably exertional heat stroke, no one should die. And it is arguably the most preventable non-traumatic exertional sudden death cause in American sports. We do a lot of work with the Israeli Defense Force. They studied their heat stroke deaths. And universally, there are two things that occur in every heat stroke death. Number one, it's physical effort unmatched to physical fitness. You've got this kid doing something he or she should not be participating in. But by far and away, it's absence of proper medical triage. We're missing. You take a look at the two key deaths, Corey Stringer and Jordan McNair, right up the road from Maryland. These were not the cooling rates. They were actually missed and delayed cooling that led to their deaths. Now this is one of the leading authorities in the world, Dr. Boucham, I'm standing right next to him. He's the intensivist in Saudi Arabia who takes care of the Hajj. At the Hajj this year, I was just looking, they had over 2,000 heat strokes, over 200 deaths, you know, with one million participants. But he's the team physician for the Hajj. And it's a big deal. He's got the formal definition. He's got several articles in the New England Journal. You've got to have a core temperature over 40 C and some kind of cognitive dysfunction. There's classic and exertional. Exertional is what we see in sports as kids are generating metabolic heat. Classic might be what you see in the Hajj where you're just absorbing that heat with low level activity. It's a heat attack. And this is what it looks like. Hopefully this plays. We can turn up the audio there a little bit. So this is Marine Corps Marathon. Someone coming in. It's going to be your patient here in just a second. We can turn up that audio. But it's a full course press for the team. You've got to be prepared. You can see this guy is flaccid. And unless somebody does something quickly, you're going to have a real problem on your hands. What does it look like? They're hot. Okay. Here you see a rectal thermist at the Marine Corps Marathon. Temperature is 107. We had a case a couple of weeks ago down at Quantico just down the road. It had a temperature of 113 in an OCS candidate. So it's not uncommon. They are inappropriate behavior. They can be comatose. They can be psychotic. They can be very combative and difficult for you to manage. You can see a seizure, but seizures especially occur during cooling. I've never, in my experience, had to manage a seizure in managing an exertional heat stroke. It is a way to get sick very fast. It's like a septic shock. It is a systemic inflammatory response. These people can go into AKI, can get a fulminant rhabdo, a bleeding diathesis, ARDS. They're going to need an intensive care multidisciplinary team if you're in the throes of a real exertional heat stroke. So just as Casey just talked about, Dr. Flanagan, you have to have a plan if you're going to be covering an event, whether it's a high school, college, or something like the Marine Corps Marathon, where you're thinking through pre-hospital management, emergency medical transport, the right equipment, do they have chilled saline on the vehicle. You've chosen the hospital ahead of time that has the ability to cool, has a nephrologist if you're going to need dialysis. This all has to be thought through so that we avoid a mistake because time is everything in exertional heat stroke. Paradigm not to forget, this again comes from the Israelis. I think it's pretty easy. You know, with trauma, we learn it's scoop and run. And that's what we do. You know, you scoop and many times the triage is done in the ambulance deciding which hospital go to. But the literature is very clear with exertional heat illness, it's cool first and then run. If you don't cool first and just load them into an EMS vehicle, I mean, it's almost a death sentence. You have to have a plan to cool on site. The other thing you should have is this document here. So this just came out, the American College of Sports Medicine, 2023 in April, a consensus document that defines best practice for the management and prevention of exertional heat stroke. It's a great read, very useful. And I'm going to be talking about several of the components. I think the core thing, as I mentioned with Corey Stringer and Jordan McNair, is identifying the athlete at risk. When you take a look at this figure here, it identified suspected heat illness, staggering, wobbly gait, cerebellar ischemia is the first part of the brain that's affected by exertional heat illness, missed assignments, unresponsive, recurrent vomiting. I mean, these are things that should trigger that you need a rectal thermistor, you need a rectal temperature, you need to make an assessment because you do not want to delay cooling. The algorithm goes forward. Now this is really important, this figure, and this is in the document. It identifies that rectangle to the left and then the triangle to the right. Now the triangle represents cooling, some form of cooling. But the errors, the fatalities, and the morbidity, at least in my experience, are not in the cooling. It's more to the left. It's the delay. It's the delay in that recognition and initiation of some cooling. That's what we need to focus on as team physicians. Now you need to have a site-specific plan for rapid cooling. I showed you a big 50-gallon immersion tub, lots of ice, lots of personnel, rectal thermistor. That may not be appropriate for your particular site. You need to do some risk assessment on what do you need. Because there are things that are more practical and things that are less practical. Again having ice and having this capability, a lot of personnel, a lot of equipment, a lot of logistics. It may not be needed for your particular event. But whatever you do, you have to have a plan. And that plan has to be executed. Now inside the article from ACSM, we identified the cooling rates from the literature. Obviously ice water immersion has some of the fastest cooling rates, but there's a lot of things that impact that. Can be body size, can be gender. You see the scatter is pretty wide from about .13 to .35. But there are other methods that are available that are a little more practical for you depending on your needs. Like this is a taco method. Literally just putting someone in a tarp, running water over them, having ice in there as you start to initiate that chain of survival. So we're very careful not to identify standard of care in the document. The document identifies best practice. And that's really up to you as the team physician. For example, down at Fort Benning, which is now Fort Moore, we use ice sheets. Ice sheets that are put into a Gatorade chest because oftentimes you're not right on top of the clinic. You may be 20 miles out and they're not going to be able to carry, you know, a 50-gallon container of chilled ice water. And just very interesting, something we just published this in 2023, we actually found a cooling rate for those people who had temperatures under 39C, about .03 to .04. You can see that's not very rapid. On the other hand, kids who had temperatures 104 and higher had very rapid cooling rates at about .16. So the higher you start, the more rapid the cooling with whatever modality that you begin with. But again, most importantly, and this is our algorithm for the Marine Corps Marathon, you have to have a plan. And if you have a morbid or mortal event, people are going to be looking at what was your plan? Did you execute the plan? This is again what we do at the Marine Corps and down at Quantico right now. You start cooling. We never give more than one to two liters of fluid. Don't want to risk exertional hyponatremia if you don't know the patient's sodium. And we stop cooling at 102, 102.5 to avoid overshoot. Oftentimes you have to warm people up afterwards, but we have seasoned teams that are ready to go. Okay. This is what it looks like right down the road at Quantico and they're dealing with this right now. I was down there last week, had four heat strokes right in front of me. If we can turn up the audio there a little bit, please. Vital signs automated and manual. There's the doctor right there. IV with blood draw, runner for incidentals, core temperature monitor, provider stationed at the patient's head and is the acting authority on treatment. Optional is an additional two active coolers. 106.5 high. Expect the patient to be violent. Watch your sharps and maintain positive control of the patient at all times. The first and most important step is to achieve a core temperature as soon as possible. Take it easy buddy, take it easy, you're all right. Don't roll in. Don't say an I. So in the essence of time, I'm not going to run the video all the way through, but the bottom line is that's a team that knows what they're doing. They're practiced. The physician's there. I like the gurney on top of the ice because I can quickly dust off the chest if I have to, dry off the chest, put an AED on if I need to, or manage an airway as opposed to deep water immersion. So again, this is the document. It also outlines recommendations for you after someone's had a heat stroke on when they can return to play, return to run. Most important point I want to make to you is that when someone has had a heat stroke and you're returning them to play, they start at ground zero. They need to be re-acclimatized to the heat. They can't go back to their team wherever they are. They're two to three weeks behind now. So in general, it takes anywhere between about three to four weeks to return someone to fitness after a heat stroke. This is defined again with this figure, this table in the document. It should be very similar to you, for those of you who manage concussion. It's very similar, moving people through medical recovery, exercise acclimatization, heat acclimatization and full return to duty. Some references. Again, the one document I think is core. This is our website. I'll have some handouts for anybody after if they'd like it. We have a Warrior Heat and Exertion Related Events Collaborative where we focus on providing consultation because once again, it's a big deal in the military. I've also got some added references here. I had a wonderful opportunity to actually write with Dr. Bushama recently an article for Nature on exertional heat stroke that for those of you interested, you might find helpful. Thank you very much.

exertional heat illness

management

heat strokes

heat exhaustions

cooling methods