| What it is | Cooling failure; medical emergency |
| Core temp | Often >104°F (40°C) |
| Key sign | Altered mental status |
| Response | Aggressive cooling + immediate evacuation |
Heat stroke is a life-threatening emergency in which the body’s temperature regulation fails, driving core temperature dangerously high (often above 104°F/40°C) with altered mental status — confusion, slurred speech, seizures, or unconsciousness. It requires immediate aggressive cooling and emergency evacuation, as it can cause organ damage or death within minutes.
This is general educational information, not medical advice. Heat stroke is an emergency — cool aggressively and call for rescue immediately.
Recognize the escalation
It is the severe end of hyperthermia, often preceded by heat exhaustion and dehydration.
Frequently asked questions
What are the signs of heat stroke?
The hallmark is altered mental status — confusion, agitation, slurred speech, irrational behavior, seizures, or loss of consciousness — combined with a very high body temperature. Skin may be hot and either sweaty or dry. Any heat illness with confusion or collapse should be treated as heat stroke.
How do you treat heat stroke?
Act immediately: it's a life-threatening emergency. Call for rescue, move the person to shade, and cool aggressively — ideally cold-water immersion, or dousing with water, fanning, and ice packs to the neck, armpits, and groin — while monitoring breathing. Rapid cooling in the first minutes is critical; evacuate to definitive medical care.
How is heat stroke different from heat exhaustion?
Heat exhaustion preserves mental function and the body's cooling still works; heat stroke is the failure of that cooling, with soaring temperature and altered consciousness. Heat stroke is a true emergency that can kill or cause permanent damage quickly, whereas heat exhaustion usually resolves with rest and cooling.
Sources
- Heat-related illness — CDC
- Heat stroke — Wilderness Medical Society