A Cool Perspective on Heat Injury
Staying Vigilant in Varied Conditions
THE PHYSICIAN AND SPORTSMEDICINE - VOL 33 - NO. 10 - OCTOBER 2022
Environmental conditions that day in Vancouver did not at all bring to mind heatstroke. Ambient temperature stayed below 21°C (70°F), with a gentle breeze off the bay. What's more, the event was a mere 10-km "fun run." Yet the medical tent saw several cases of hyperthermia—and I had the sore ribs to prove it.
Those treated for temperatures above 40°C (104°F) were typically unconditioned, overweight, and overdressed. Diagnosis was fairly straightforward, because all runners exhibited altered mentation, such as incoherence, belligerence, and combativeness. One such affected female runner took umbrage at my approach to medicine and connected with a right cross to my torso. Rectal temperatures (not easy to take with uncooperative patients) clinched the diagnosis, and, after peeling off the runners' sweatshirts and other heavy clothing, we began immediate whole-body cooling.
This experience in cool climes underscores the fact that we need to be vigilant for heatstroke in all kinds of environmental conditions, so keep it in mind during road races and other athletic events this fall. (While also staying alert to the dangers of hyponatremia, especially in slower runners during longer races.)
Heatstroke has also been in the news of late, especially with the publication in August of guidelines from the American College of Sports Medicine (ACSM) on heat injury in football.1 At least two athletes—both football players—died this year from heatstroke.
That's why we strive to provide you with the best thinking and evidence on heatstroke diagnosis, care, and prevention. This month we publish commentaries from two leading experts on our Editorial Board, Timothy D. Noakes, MBChB, MD, DSc, and William O. Roberts, MD.
Noakes, a veteran of many marathons and ultramarathons—both as a participant and as a race physician—is widely published on exercise-related topics such as dehydration, hyponatremia, exercise-associated collapse, and heat injury, as well as the author of the popular book, Lore of Running. In his commentary, Noakes emphasizes the role of a healthy brain in regulating the body's rate of heat production during exercise. His point is that applying the "normal" precautions, such as hydration and avoiding exercise in extreme heat, will never be completely effective if heatstroke is more often caused by a failure of brain regulatory mechanisms associated with biochemical abnormalities. Therefore, scientists should look for more obscure causes of heatstroke, such as muscle metabolic abnormalities and other unusual environmental influences.
Although Roberts, immediate past-president of ACSM and medical director of the Twin Cities Marathon, does not disagree with Noakes' premises, he lends his own view on the topic, primarily based on cases he's studied or witnessed. He sees heatstroke cases as somewhat random events that share several common threads, including lack of acclimatization; "other" factors like viral illness, ephedra use, or a genetic predisposition; extraordinary effort on the part of the athlete; and a lack of immediate recognition of the condition. Roberts also offers several practical tips for reducing the incidence of heat injury.
We hope these commentaries help you with the next patient that you suspect as having hyperthermia. I know now that heatstroke prevention means more than a rectal thermometer and sore ribs.