Bookmark this page

Extreme Heat

Protect your health and the health of your family when it's very hot

Heat-related illnesses are preventable - prepare for the heat in advance

  • Beat the heatTune in regularly to local weather forecasts and alerts so you know when to take extra care.
  • Arrange for regular visits by family members, neighbours or friends during very hot days in case you need assistance. Visitors can help identify signs of heat illness that could be missed over the phone.
  • If you have an air conditioner, make sure it works properly before the hot weather starts. Otherwise, find an air-conditioned spot close by where you can cool off for a few hours during very hot days. This will help you cope with the heat better.
  • Learn about ways to keep your home cool during the summer. For example, if you live in a house, plant trees on the side where the sun hits the house during the hottest part of the day.

During extreme heat protect your health

Watch for symptoms of heat illness, which include:
  • dizziness or fainting
  • nausea or vomiting
  • headache
  • 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.

Stay Hydrated

  • 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.
  • Remind yourself to drink water by leaving a glass by the sink.Girl drinking water
  • Flavouring water with natural fruit juice may make it more appealing.
  • Eat more fruits and vegetables as they have a high water content.
  • If you eat less, you may need to drink more water.
  • Drink water before, during and after physical activity.

Stay Cool

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, remove gear to let your body cool off and drink lots of water. 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 opening awnings, closing curtains or blinds during the day.
  • If safe, 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 22°C/72°F and 26°C/79°F). This will reduce your energy costs and provide you with needed relief. If you are using a window air conditioner, cool only one 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 air flow 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

Never leave people or pets inside a parked vehicle or in direct sunlight

  • When the outside air temperature is 23°C/73°F, the temperature inside a vehicle can be extremely dangerous - more than 50°C/122°F.

Reschedule or plan outdoor activities during cooler parts of the day

  • Before heading out, check the Air Quality Health Index in your area, if available. Air pollution tends to be at higher levels during very hot days.
  • Plan strenuous outdoor activities for cooler days, or choose a cooler location like a place with air conditioning or with tree shade.

Find or bring shade when possible

  • Tree-shaded areas can be as much as 5°C/9°F cooler than the surrounding area.
  • Shade yourself by wearing a wide-brimmed, breathable hat, or using an umbrella.
  • Wear loose-fitting, light-coloured clothing made of breathable fabric.
  • Wear sunglasses that have UVA and UVB protection.
  • Use a sunscreen with sun protection factor (SPF) 15 or higher and follow the manufacturer's directions. Don't use sunscreen on a child less than 6 months old.