Extreme heat events: How to protect yourself from the health effects of extreme heat
On this page
- Prepare for the heat
- Pay close attention to how you, and those around you, feel
- Stay hydrated
- Stay cool
- Avoid exposure to extreme heat when outdoors
Prepare for the heat
- Tune in to local weather forecasts and alerts so you know when to take extra care.
- Find ways to keep cool before the hot weather starts. If you have an air conditioner, make sure it works properly. If you have ceiling fans or other fans, they can help as long as the humidity isn't high. Find an air-conditioned spot close by where you can cool off for a few hours on very hot days. This will help you cope with the heat.
- Have cool drinks in your vehicle and keep your tank filled or car charged in case you need to get somewhere cool quickly.
- Arrange for regular visits by family members, neighbours or friends during very hot days in case you need help. Visitors can help identify signs of heat illness that could be missed over the phone.
Pay close attention to how you, and those around you, feel
Heat stroke is a medical emergency.
Call 911 or your local emergency number immediately if you are caring for someone who has a high body temperature and is either unconscious, confused or has stopped sweating.
Watch for symptoms of heat illness, which include:
- nausea or vomiting
- dizziness or fainting
- rapid breathing and heartbeat
- extreme thirst (dry mouth or sticky saliva)
- decreased urination with unusually dark yellow urine
- changes of behaviour in children (like sleepiness or temper tantrums)
If you have any of these symptoms during extreme heat, move to a cool place and drink liquids right away. Water is best.
While waiting for help, cool the person right away by:
- fanning the person as much as possible
- moving them to a cool place, if you can
- applying cold water to large areas of their skin or clothing
Drink plenty of cool liquids (especially water) before you feel thirsty to decrease your risk of dehydration (not having enough fluids in your body). Thirst is not a good indicator of dehydration.
- If you eat less, you may need to drink more water.
- Drink water before, during and after physical activity.
- Remind yourself to drink water by leaving a glass by the sink.
- Eat more fruits and vegetables as they have a high water content.
- Flavouring water with natural fruit juice may make it more appealing.
Did you know?
Your body isn't used to extreme heat at the beginning of the summer. If you're physically active, you're also not used to extreme heat if you don't exercise regularly during hot weather.
Dress for the weather
- Wear loose-fitting, light-coloured clothing and a wide-brimmed hat made of breathable fabric.
- When you buy sunglasses, make sure they provide protection against both UVA and UVB rays.
Take a break from the heat
- If you must do physical activity in extreme heat:
- take extra breaks
- drink lots of water
- remove gear to let your body cool off
- Don't expect your usual performance in hot weather. Give your body time to recover after being in the heat.
Keep your home cool
- Make meals that don't need to be cooked in an oven.
- Block the sun by closing awnings, curtains or blinds during the day.
- If possible, open your windows at night to let cooler air into your home.
- If you have an air conditioner with a thermostat, keep it set to the highest setting that is comfortable (somewhere between 22ºC/72ºF and 26ºC/79ºF). This will reduce your energy costs and provide you with needed relief. If you are using a window air conditioner, cool only 1 room where you can go for heat relief.
If your home is extremely hot
- Take cool showers or baths until you feel refreshed.
- Use a fan to help you stay cool and aim the airflow in your direction.
- Spend a few hours in a cool place. It could be a tree-shaded area, swimming facility or an air-conditioned spot like a shopping mall, grocery store or public library.
Avoid exposure to extreme heat when outdoors
Did you know?
Sunburned skin loses its sweating efficiency. This makes it harder for your body to regulate its temperature.
Never leave people or pets inside a parked vehicle or in direct sunlight.
- When the outside air temperature is 23ºC/73ºF, the temperature inside a vehicle can be extremely dangerous at more than 50ºC/122ºF.
Reschedule or plan outdoor activities during cooler parts of the day.
- Plan strenuous outdoor activities for cooler days.
- Choose a cooler location like a place with air conditioning or a spot with shade such as from a tree.
- Tree-shaded areas can be as much as 5ºC/9ºF cooler than the surrounding area.
Avoid sun exposure. Find or bring shade when possible.
- Use an umbrella.
- Choose a spot with shade such as from a tree or awning.
Report a problem or mistake on this page
- Date modified: