Which symptom distinguishes heat stroke from heat exhaustion?

• A. Dry skin
• B. Pale and clammy skin with rapid pulse
• C. Excess sweating
• D. Normal body temperature

Answer: (A)

The key idea is how the body's cooling mechanism changes under extreme heat. In heat exhaustion, the body is still trying to cool itself, so sweating continues and the skin tends to be moist, pale, and clammy. In heat stroke, the body's thermoregulation fails and sweating often stops, leaving the skin dry and hot. That dry skin is a telltale sign that heat stroke may be developing, and it signals a dangerous level of heat stress that requires urgent care.

So the symptom that best distinguishes heat stroke from heat exhaustion is dry skin. Other signs, like pale and clammy skin with a rapid pulse or excess sweating, are more consistent with heat exhaustion. Normal body temperature would not fit heat stroke, which involves a very high core temperature.