Heat exhaustion and heat stroke¶
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 happens when the body cannot cool itself fast enough. This page helps you tell mild heat exhaustion from life threatening heat stroke, and shows you how to cool someone down.
Do this now¶
- Move the person out of the sun and heat, into shade, air conditioning, or the coolest place you can find.
- Call your local emergency number if they are confused, faint, have hot skin that is not sweating, or have a seizure (911 in the United States and Canada, 112 across the European Union, 999 in the United Kingdom).
- Take off extra clothing and start cooling the skin right away with cool water, wet cloths, and a fan.
- If they are awake and able to swallow, give small sips of cool water.
- Stay with them until they recover or help arrives.
Heat exhaustion or heat stroke?¶
Heat exhaustion is the milder stage. Heat stroke is an emergency, and it can start with no clear warning.
| Heat exhaustion | Heat stroke | |
|---|---|---|
| Skin | Heavy sweating, pale and clammy | Hot, red or dry, may stop sweating |
| Mind | Tired, irritable, dizzy | Confused, agitated, slurred speech |
| Other signs | Headache, nausea, muscle cramps, strong thirst | Fast pulse, fast breathing, seizure, passing out |
| What to do | Cool down and rest | Call for emergency help and cool at once |
If you are not sure which one it is, treat it as heat stroke.
... danger "Heat stroke can kill" A person with heat stroke needs emergency care. Call your local emergency number first, then cool them while you wait. Do not wait to see if they get better on their own.
How to cool someone down¶
Cooling quickly matters most. Use whatever you have.
- Move them to shade or a cool room, and lay them down.
- Remove extra clothing and shoes.
- Wet the skin with cool water, or cover them with wet sheets or towels, and fan them.
- Place cold packs or wrapped ice on the neck, armpits, and groin, where large blood vessels run close to the skin.
- If they are alert, give small sips of cool water, or an oral rehydration drink if you have one.
Do not give anything to eat or drink to a person who is confused, vomiting, or not fully awake. If they stop responding and are not breathing normally, start CPR.
Mild heat exhaustion¶
If the person is alert and only has the milder signs, cool them and have them rest in a cool place. They should start to feel better within about 30 minutes, according to UK health guidance. If they are not better after 30 minutes, or if any heat stroke sign appears, call your local emergency number.
Sports drinks or oral rehydration salts can help replace what sweating has taken. Stay indoors or in shade for the rest of the day, and do not return to hard work or exercise until fully recovered.
Who is at higher risk¶
Heat illness can happen to anyone, but some people get sick faster:
- Babies and young children
- Older adults
- People who work or exercise outdoors
- People with heart, lung, or kidney conditions, or who take some medicines
- People who are dehydrated, or who have been drinking alcohol
Never leave a child or pet in a parked car, even for a short time. The inside of a car can become dangerously hot within minutes.
Prevent it¶
- Drink water often, before you feel thirsty
- Wear light, loose, light colored clothing and a hat
- Rest in shade and avoid hard work in the hottest part of the day
- Check on older neighbors and relatives during hot weather
- Know where the nearest cooling center is, if your area opens them
For longer hot spells, read our guide to extreme heat.
... note "Take a course" A Red Cross or similar first aid course teaches you to recognize heat illness and other emergencies with hands on practice. It is good preparation for the next one.