How do heat exhaustion and heat stroke differ?

• A. They are the same condition.
• B. Heat exhaustion is dehydration with fatigue and elevated but not extreme core temperature; heat stroke is a medical emergency with core temperature typically above 40 C (104 F) and altered mental status.
• C. Heat stroke occurs only in cold weather.
• D. Heat exhaustion always requires hospitalization.

Answer: (B)

The important difference is how severe the condition is and whether the brain is affected. Heat exhaustion comes from dehydration and overheating and presents with fatigue, dizziness, headache, nausea, and a temperature that is elevated but not dangerously high. It usually gets better with cooling, fluids, and rest. Heat stroke is a medical emergency: core temperature climbs to about 40 C (104 F) or higher and there is altered mental status such as confusion, agitation, seizures, or coma. Because of the risk of brain and organ damage, it requires urgent medical care and rapid cooling, often with professional monitoring and support.

Heat stroke can occur in hot weather and during intense activity, and sometimes sweating is still present, especially in exertional cases, while heat exhaustion does not involve such a high temperature or CNS changes. Also, heat exhaustion doesn’t always require hospitalization, whereas heat stroke demands immediate emergency treatment.