Exertional heat stroke and exertional heat exhaustion differ in terms of core temperature and CNS involvement. Which statement is correct?

• A. Heat stroke features CNS dysfunction with core temperature typically above 40°C; heat exhaustion lacks CNS impairment and has lower core temps or normal range with dehydration signs.
• B. Heat stroke has no CNS issues; heat exhaustion has severe CNS dysfunction.
• C. Both have same core temperature; only dehydration differs.
• D. Heat stroke occurs only in cold weather.

Answer: (A)

The key idea is that distinguishing exertional heat illness relies on CNS effects and how high the body's core temperature rises. Exertional heat stroke is defined by central nervous system dysfunction — such as confusion, agitation, or seizures — together with a markedly elevated core temperature, typically above 40°C (104°F). That combination signals a life-threatening emergency and requires rapid cooling and advanced care.

Exertional heat exhaustion, on the other hand, presents with dehydration, weakness, dizziness, and fatigue, but the CNS remains intact (no significant mental status change). The core temperature is usually normal or only mildly elevated, not in the heat-stroke range. Management focuses on fluids, rest, and cooling to address dehydration, not the aggressive cooling required for heat stroke.

So this statement is best because it correctly links CNS impairment and very high core temperature with heat stroke, while describing the absence of CNS impairment and lower or normal core temperature with heat exhaustion. The other options contradict these fundamental distinctions (for example, heat stroke does involve CNS issues, and them having the same core temperature or occurring only in cold weather isn’t accurate).