Extreme heat: staying safe in a heat wave¶
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.
A heat wave is a period of unusually high heat, often with high humidity, lasting several days. This page helps you stay cool, look out for others, and act early.
Do this now¶
- Get to a cool place. Use air conditioning, or go to a cooling center, library, or other public building.
- Drink water often, even if you do not feel thirsty.
- Stay out of the sun, and rest during the hottest part of the day.
- Check on family, neighbors, and older adults.
- If someone is confused, faint, or has hot, dry skin, call your local emergency number (911 in the United States and Canada, 112 across the European Union, 999 in the United Kingdom).
Stay cool¶
The body cools itself by sweating, and in extreme heat that may not be enough.
- Stay in air conditioning if you can, or in the coolest, lowest room
- Wear loose, light colored, light clothing
- Take cool showers or baths
- Close blinds and curtains on sunny windows by day
- Open windows at night only if the air outside is cooler
- Avoid hard work or exercise outdoors in the heat, and do it early or late if you must
- Use the oven and stove less to keep the house cooler
A fan alone does not stop heat illness in very hot weather. It can help a little with a cool, wet cloth on the skin, but it will not lower your body temperature in extreme heat.
Never leave anyone in a parked car¶
A car can heat up in minutes, even with the windows cracked. Never leave a child, an older person, or a pet in a parked car, even for a short time.
Check the back seat every time you leave your car. If you see a child or pet in distress in a locked car, call your local emergency number.
Check on others¶
Heat is most dangerous for older adults, babies, young children, people who live alone, people who work outdoors, and people with health conditions.
Visit or call neighbors and relatives at least once a day. Help them get to a cool place, and bring water. Ask what medicines they take, because some make heat illness more likely.
Cooling centers¶
If your home does not have air conditioning, or it is too hot to stay cool, go somewhere that does. Local governments often open cooling centers during heat waves. Ask your local emergency office or health department, and do not wait until you feel ill. In the United States, you can often call 211.
Know the signs of heat illness¶
Heat illness can move from mild to life threatening. Watch for heavy sweating, muscle cramps, dizziness, headache, nausea, and weakness. If you notice them, move to a cooler place, loosen clothing, and sip water.
... danger "Heat stroke is an emergency" A very high body temperature, hot and dry skin, confusion, or fainting are signs of heat stroke. Call your local emergency number at once. Move the person to shade or a cool room, and cool them with cold wet cloths or cold water until help comes.
Our guide on heat illness explains each stage and what to do in more detail.
Pets and animals¶
Give pets plenty of cool water and shade, and keep them indoors in the hottest hours. Hot pavement can burn their paws, so walk them early or late. Animals left outside need shelter from the sun.
Plan ahead¶
Heat waves are often forecast days ahead. Know where the nearest cooling center is, check that your fan or air conditioner works, and store water. Ask your doctor or pharmacist about heat and any medicines you take.
... tip "Look out for yourself too" Do not wait until you feel unwell to cool down. People often feel fine until heat illness is well under way.