Which of the following conditions is NOT classified as an exertional heat illness?

Hypothermia is not classified as an exertional heat illness because it is a condition that occurs when the body loses heat faster than it can produce it, leading to dangerously low body temperatures. This typically happens in cold environments or situations rather than as a result of exertion in heat. In contrast, exertional heat illnesses, such as heat rash, heat cramps, and heat stroke, all relate to the body's inability to dissipate heat efficiently during physical activity, leading to overheating. These conditions are directly connected to high environmental temperatures or intense physical exertion, whereas hypothermia arises from the opposite issue of excessive heat loss.