Heat Stroke vs Heat Exhaustion Identification and First Aid¶
Emergency numbers differ by country. This page uses 911, the number for the United States and Canada. Many other countries use 112, 999, or another number. Find the number for your country.
Heat illness occurs when the human body cannot regulate its internal temperature during exposure to extreme heat. Distinguishing between heat exhaustion and heat stroke is critical, as heat stroke is a life-threatening medical emergency requiring immediate emergency services.
If someone collapses, exhibits confusion, or loses consciousness in heat, call 911 or your local emergency number immediately.
Key Differences¶
| Symptom / Sign | Heat Exhaustion | Heat Stroke (Life Threatening) |
|---|---|---|
| Mental State | Alert, tired, dizzy | Confused, altered, slurred speech, unconscious |
| Body Temperature | Under 40 °C (104 °F) | Above 40 °C (104 °F) |
| Skin State | Heavy sweating, pale, cold, clammy | Hot, red, dry or heavily sweating |
| Pulse | Fast and weak | Fast and strong |
| Nausea / Vomiting | Possible nausea or vomiting | Nausea, vomiting, possible seizures |
Immediate First Aid for Heat Exhaustion¶
- Move to a Cooler Location: Transfer the person into an air-conditioned room or shady, ventilated area.
- Loosen Clothing: Remove heavy or extra layers of clothing.
- Apply Cool Compresses: Place cool, damp cloths on the neck, armpits, and groin. Spray cool water or fan the person gently.
- Provide Fluids: Have the person sip cool water slowly if they are fully conscious and able to swallow. Do not offer alcohol or caffeinated beverages.
- Monitor Closely: If symptoms worsen or fail to improve within 30 minutes, call emergency services immediately.
Immediate Emergency First Aid for Heat Stroke¶
- Call Emergency Number Instantly: Call 911 or your local emergency service right away.
- Initiate Rapid Cooling:
- Immerse the person up to their neck in a cold water bath if safe and available.
- If cold bath immersion is unavailable, cover the body with ice packs or cold wet towels continuously while fanning vigorously.
- Do Not Give Fluids: Do not attempt to force water or fluids down an unconscious or confused person's mouth.
- Position for Breathing: If the person is unconscious but breathing normally, place them in the side-lying recovery position to keep their airway clear.
Taking a certified first aid and CPR course through the Red Cross, St. John Ambulance, or local health organizations provides hands-on practice for heat illness emergency response.