Which condition results from heat exposure involving loss of the body's heat balance?

• A. Heat stroke
• B. Heat exhaustion
• C. Heat rash
• D. Sunburn

Answer: (A)

Heat stroke happens when heat exposure overwhelms the body's ability to regulate temperature, causing a loss of heat balance. When the body is overheated, the thermoregulatory system can fail—sweating may stop and blood vessels can’t dissipate heat effectively—so core temperature rises to dangerous levels. This breakdown of the body's heat balance makes heat stroke the most severe and life-threatening heat-related illness. Look for signs like very high body temperature, confusion or altered mental status, seizures, and signs of heat distress. It’s a medical emergency requiring immediate cooling and medical care.

Heat exhaustion, by contrast, is mainly due to dehydration and electrolyte loss with continued sweating, leading to fatigue, dizziness, and low blood pressure but typically still some sweating and less dramatic temperature rise. Heat rash is simply skin irritation from sweating, and sunburn results from UV damage, not from the body's heat balance failing.