Extreme heat can affect your health and can increase the risk of heat-related illnesses, especially for those most vulnerable. Many heat-related illnesses can be prevented.

Taking simple steps such as drinking water regularly, reducing strenuous activity during hot weather and spending time in air-conditioned spaces when possible can help protect your health. For information on your local forecast and weather alerts, visit Environment and Climate Change Canada or download the WeatherCAN mobile app.

Use the information below for tips on how to keep cool at home and outdoors, recognize signs of heat-related illness and prepare before it gets hot.

Stay hydrated

  • Drink plenty of water, even before you feel thirsty.
  • Add ice to help cool your body.

Dress for the heat

  • Wear loose, light-coloured breathable clothing and a wide-brimmed hat.
  • Protect yourself from the sun.

    Limit activity during peak heat

    • Limit time in the sun. Plan outdoor activities early in the morning or evening.
    • Choose shaded or air-conditioned spaces.
    • Seek shade when outdoors for extended periods and keep in mind that shaded areas move throughout the day as the sun changes position.

    Know where to go to cool down

    • Don’t wait until you feel unwell. Take a break for 2 to 3 hours in a shaded or air-conditioned space.
    • The Heat Relief Network has 500 welcoming locations. Find one near you.
    • Public parks and recreation facilities offer access to drinking water and washrooms. Find nearby locations.

    Never leave people or pets in a parked vehicle

    • Vehicles can heat up quickly, even with windows open.  
    • Be sure to check the back seat before you lock the car.

    Block the sun

    • Close blinds or drapes during the hottest part of the day.
    • Use curtains or shade to help control light and reduce heat and sunlight coming through the windows that face the sun.

    Bring in cooler air

    • Open windows at night when the air outside is cooler than inside your home.
    • Use portable fans in front of open windows to draw in evening air and help cool key rooms. 
    • Use draft stoppers or seal gaps to keep cool air inside.

    Take a break in cool or air-conditioned spaces

    • If you have an air conditioner, make sure it is working properly before periods of hot weather.
    • If possible, keep the rooms you use most often cool, especially sleeping areas.
    • On very hot days, if your home is not air-conditioned, find an air-conditioned spot nearby where you can cool off for a few hours. This will help you cope with the heat.

    Avoid adding heat

    • Limit use of appliances that generate heat, such as the oven, dryer or dishwasher.
    • Choose no-cook meals and keep food preparation light and simple.
    • Turn off unnecessary lights and electronics where possible.

    Cool down with water

    • Take a cool shower, wear a wet shirt or use damp cloths on your body. This helps to lower your body temperature quickly.

    Monitor indoor temperature

    • Use an easy-to-read thermometer. Sustained indoor temperatures above 26 degrees Celsius can affect health, especially for people vulnerable to heat. Seek cooler spaces for at least 3 hours a day if indoor temperatures reach 31 degrees Celsius or higher.
    • If indoor temperatures are uncomfortable or stay above 26 degrees Celsius, go to a cooler indoor or air-conditioned space.
    • Risk of heat illness increases with sustained indoor temperatures of 31 degrees Celsius or higher. Older adults, people with health conditions and others at risk of heat illness are recommended to seek cooling options. 

    Schedule visits

    • Ask family, friends and neighbours to check on you at home during very hot days in case you need help, especially if you live alone and have a health condition or you’re an older adult living alone.

    Check on others

    • Call, text or visit neighbours, friends and family during hot weather. If possible, visit them in person to see how they are doing and whether their space is cool enough.
    • If calling or texting, ask questions such as:
      • Are you drinking enough water?
      • Is your home cool enough?
      • How hot does it feel indoors? Do you know the temperature?
      • Do you need help getting to a cooler place?
    • During extreme heat, check more often on people at higher risk, including older adults, especially those living alone, people with health conditions and those who work or are active outdoors.
    • Place your fan near an open window. Box fans are best.
    • Plug fans directly into a wall outlet. If you need an extension cord, use one approved by the Canadian Standards Association (CSA).
    • Do not use a fan in a closed room without open windows or doors to the outside.
    • Fans do not cool air or lower the room temperature of a room. They help cool your body by moving air around and by evaporating sweat.
    • Avoid blowing extremely hot air on yourself. This can increase the risk of heat exhaustion.
    • If you do not feel comfortable opening your window to use a fan, choose other ways to keep cool. See the additional cooling tips on this page.
    • Do not use fans when the temperature in a room is 34 degrees Celsius or higher. At very high temperatures fans can increase heat exposure instead of cooling you down. This is especially important for older adults and people taking certain medications who may have a decreased ability to sweat.

    If your child gets locked inside a car, or if you witness a child left in a hot car, call 911 immediately.

    Temperatures inside a vehicle can heat up quickly during warm weather, creating a dangerous environment that may cause serious harm or death.

    During the summer, as the outside air temperature increases, temperatures inside a vehicle can reach dangerously high levels. Opening the car window slightly or parking in the shade does not keep a vehicle at a safe temperature.

    Why parked cars are dangerous

    Young children, especially infants, are much more sensitive to heat than adults. Even on mild or warm days, rising temperatures inside a vehicle can lead to significant heat stress on children causing severe dehydration, heat exhaustion or heat stroke.

    What parents and caregivers need to know

    • Never leave a child in an unattended vehicle, even with the windows open.
    • Teach children not to play in, on, or around vehicles.
    • Always lock car doors and trunks when parked in the driveway or near your home so that children do not play in them and become trapped.
    • Before leaving your vehicle, check that all children have exited the vehicle safely, including sleeping infants and young children.
    • Check the temperature of your child’s car seat surface and seat belt buckles before use. Your child’s skin can be severely burned when coming in contact with car seat surfaces that are dangerously hot.
    • Keep car keys out of reach and out of sight of children.
    • Give pets plenty of fresh, clean water when it’s hot or humid outdoors as pets can get dehydrated quickly. Make sure your pets have a shady place to get out of the sun, be careful not to over-exercise them and keep them indoors when it’s extremely hot.
    • Know the symptoms of overheating in pets, which include excessive panting or difficulty breathing, increased heart and respiratory rate, drooling, mild weakness, stupor or even collapse. Symptoms can also include seizures, bloody diarrhea and vomit along with an elevated body temperature of over 40C/104F degrees (normal body temperature range is 38.3C/101F – 39.2C/102.5F).
    • Never leave your animals alone in a parked vehicle. It can lead to fatal heat stroke.
    • Know that animals with flat faces, like Pugs and Persian cats, are more susceptible to heat stroke since they cannot pant as effectively. These pets, along with the elderly, the overweight and those with heart or lung diseases, should be kept cool in air- conditioned rooms as much as possible.
    • Feel free to trim longer hair on your dog but never shave your dog. The layers of dogs’ coats protect them from overheating and sunburn. Brushing cats more often than usual can prevent problems caused by excessive heat. And be sure that any sunscreen or insect repellent product you use on your pets is labeled specifically for use on animals.
    • Don’t let dogs linger on hot asphalt when the temperature is very high. Being so close to the ground, your pooch’s body can heat up quickly, and sensitive paw pads can burn. Keep walks during these times to a minimum.
    Date modified: May 26, 2026