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. 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.
• Keep your gas 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

Watch for symptoms of heat exhaustion, which include:

• headache
• 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.

If you or anyone in your care experiences any of these signs and symptoms, call 911 immediately. 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

Stay hydrated

Drink plenty of water before you feel thirsty to decrease your risk of dehydration (not having enough fluids in your body). You may be dehydrated even if you are not thirsty. Stay hydrated.

• 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.
• Add fruit or herbs to water for flavour, if desired.

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
  • 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. Try Canada's food guide's no-cook recipes.
• 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, be sure to turn it on before it gets hot. 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. Note: While fans can help you feel more comfortable, they are ineffective at cooling the body at temperatures over 35°C.
• Spend time 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.

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.

Avoid sun exposure. Find or bring shade when possible.

• Use an umbrella.
• Choose a spot with shade such as from a tree or awning.