RAAF Mission Aircrew ATC Practice Exam

Exertional heat exhaustion arises when environmental heat stress and strenuous physical exercise together overwhelm the body's ability to shed heat and maintain fluid balance. During hard work in a hot environment, the body generates a lot of heat and relies largely on sweating to cool off. When sweating leads to significant fluid and electrolyte loss, blood volume drops and the skin’s blood flow for cooling is compromised. Core temperature rises enough to cause fatigue, weakness, dizziness, headache, nausea, and a rapid heart rate, with cool, clammy skin and normal or slightly altered mental status. The crucial point is that both the hot environment and the heavy physical activity are needed to produce this condition; cold environments or low humidity alone don’t create the same heat load. Dehydration from cold weather can occur, but it isn’t exertional heat exhaustion driven by heat stress.

If this condition is suspected, move the person to a cooler area, remove excess clothing, have them rest, and rehydrate with cool fluids if conscious. Apply cooling methods such as fanning or cooling with water or immersion if available, and monitor for worsening symptoms or signs of heat stroke (such as confusion, loss of consciousness, or very hot, dry skin), which require immediate medical attention.