Who is most at risk?
Extreme heat poses greatest health risks to:
- Older adults
- Infants and young children
- People with chronic illnesses (heart disease, breathing problems, mental illness)
- People without air conditioning
- People who work or exercise in the heat
BEFORE summer: Prepare your home for extreme heat
Cool your home
- Test air conditioners in spring to ensure they work properly
- If you have no air conditioning: Make arrangements to access a nearby cool space such as a shopping mall, library, or community centre for a few hours on very hot days
- Block sunlight by closing awnings, curtains, or blinds during the day
- Open windows at night to let cooler air into your home when it is cooler outside
Prepare for heat illness
Heat can cause several illnesses that need different responses:
Heat exhaustion includes: headache, nausea or vomiting, dizziness or fainting, rapid breathing and heartbeat, and extreme thirst. If you experience these, move to a cool place and drink liquids right away. Water is best.
Heat stroke is a medical emergency. Signs include high body temperature, confusion and lack of coordination, or very hot or red skin. Call 911 immediately. While waiting for help, cool the person by fanning, moving them to a cool place, or applying cold water to large areas of skin.
Create a household heat plan
- Identify which room will be your main cool space
- Know locations of nearby cooling centres
- Arrange regular check-ins with family and neighbours during summer heat
DURING a heat wave: Stay in a cool room and keep hydrated
Keep your home and body cool
- Remain in air-conditioned or shaded spaces during the hottest hours
- Close windows and curtains during the day
- Open windows early morning and evening when it is cooler outside
- Sleep on the coolest floor since heat rises
Drink plenty of water
- Drink water before, during, and after physical activity
- Drink plenty of water before you feel thirsty to decrease your risk of dehydration. You may be dehydrated even if you are not thirsty.
- Eat fruits and vegetables with high water content
Protect yourself outdoors
- Wear loose-fitting, light-coloured clothing and a wide-brimmed hat made of breathable fabric
- Reschedule or plan outdoor activities during cooler parts of the day
- Never leave people or pets inside a parked vehicle or in direct sunlight
- Avoid strenuous outdoor activities during peak heat hours
Use fans correctly
- Fans are ineffective at cooling the body at temperatures over 35°C — instead use air conditioning or go to a cooling centre
- Use a fan to help you stay cool and aim the airflow in your direction at lower temperatures
Check on vulnerable people daily
- Call or visit older adults, people living alone, and those with health conditions
- Ensure they have access to cool spaces and water
- Watch for heat exhaustion and heat stroke signs
- Help with errands so they do not go out in extreme heat
If home cooling fails
- Go to a cooling centre or friend's place with air conditioning
- Use wet cloths and ice packs on neck, wrists, and armpits to cool
- Take cool showers or baths until you feel refreshed
AFTER a heat wave
- Continue drinking water — dehydration can last after the heat ends
- Rest and let your body recover
- Check on vulnerable people to ensure they are recovering
Key reminders
- Older adults, infants, and children are most at risk from extreme heat
- Heat illness is preventable — keep cool and stay hydrated
- Fans do not work above 35°C — use air conditioning instead
- Never leave people or pets in vehicles in the heat