Exertional Heat Stroke and Exercise-Associated Hyponatremia in Collapsed Endurance Athletes

When evaluating a collapsed endurance athlete, sudden cardiac arrest, exertional heat stroke (EHS) and exercise-associated hyponatremia (EAH) are important conditions that must be considered to avoid a catastrophic outcome. It is important to cool EHS victims on site within 30-60 minutes (min) of collapse by any means available to reduce morbidity and mortality. Methods include cold-water immersion, tarp-associated cooling (TACO), and rapidly rotating ice water soaked towels. Signs and symptoms of EHS may overlap with those of EAH. However, a history of hyperhydration combined with an exercise duration greater than four hours (h) is typical for EAH. Neurological signs and symptoms along with elevated rectal temperatures are required to make the diagnosis of EHS. The objective of this narrative review is to summarize the current literature for medical personnel to better understand, assess, and manage EHS and EAH on site.