How can you differentiate heat stroke from heat exhaustion in the field?

• A. Heat stroke presents with altered mental status or confusion; heat exhaustion does not; both require cooling and hydration, with more urgent cooling for heat stroke.
• B. Heat stroke occurs with rapid dehydration; heat exhaustion occurs with confusion
• C. Heat stroke has no sweating; heat exhaustion has sweating
• D. There is no difference in mental status between heat stroke and heat exhaustion

Answer: (C)

In the field, you distinguish heat stroke from heat exhaustion by how the body’s cooling system is working, which shows up quickly as sweating status. Heat stroke happens when thermoregulation fails, and sweating often stops, leaving the skin dry and hot while the person may develop altered mental status such as confusion or agitation. Heat exhaustion, on the other hand, usually keeps the person sweating; the skin tends to be moist and cool, and the individual may feel weakness, dizziness, or nausea but remains more alert.

This sweating pattern is a practical, observable cue that helps you triage the immediacy of the threat. Heat stroke is a medical emergency requiring rapid cooling and urgent EMS involvement, because the CNS dysfunction and extreme hyperthermia carry a high risk of death. Heat exhaustion still needs cooling and fluids, but is less immediately life‑threatening. While mental status changes can occur in both, the presence or absence of sweating provides a quick, actionable way to tell them apart in the field.