The definition of extreme heat varies depending on the region of Québec. Generally, it is defined as temperatures between 31 and 33°C during the day and between 16 and 20°° °C at night for three consecutive days.
In Canada, heat warnings are issued by Environment Canada when one of the following conditions is expected to last for at least one hour:
a temperature of 30°C or higher and a humidex rating of 40 or higher.
a temperature of 40°C or higher.
On this page:
Preparing for a heat wave
Find out about weather conditions in your sector. Plan your activities taking into account extreme heat forecasts.
Never leave a child or pet alone in a car, even for a few minutes, even if the windows are open.
For adults
During a heat wave, your health can deteriorate quickly. Take certain precautions to improve your comfort and reduce the risks to your health and the health of your loved ones.
Stay hydrated:
Drink plenty of water without waiting until you feel thirsty.
Make sure you have access to sufficient drinking water during heat warnings.
Avoid alcoholic beverages, as alcohol can worsen dehydration.
Cool down often:
Take a cool shower or bath, or swim in a pool, if possible.
Apply cool, wet cloths to your face, arms, and neck, and spray your face with cool water several times a day.
Spend as much time as possible, at least two hours per day, in an air-conditioned or cool place (e.g., an air-conditioned room in your home, a library, or an air-conditioned shopping mall).
Protect yourself from the heat:
Wear light, loose-fitting, pale-colored clothing. Wear a wide-brimmed hat made of breathable fabric.
Adjust your physical activity by taking more frequent breaks and drinking plenty of water.
Do physical activities or sports when it is cooler (e.g., before 11 a.m. or after 6 p.m.) or in an air-conditioned place.
Close windows, curtains, or blinds when the sun is shining to limit indoor heating.
Open windows to refresh the air when the outside temperature is lower than the indoor temperature, for example at night.
Promote air circulation, for example by using a standing fan.
Minimize the use of appliances that give off heat (stove, oven, dryer, television, lights, etc.).
Check in on your loved ones and don't hesitate to ask for help from those around you during periods of extreme heat:
Elderly people or those with chronic illnesses who live alone should check in with their loved ones and not hesitate to ask for help from those around them.
Relatives of elderly people, people who are becoming less autonomous, or those who live alone should visit them regularly.
Follow the recommendations of Environment Canada or your region's public health department during an extreme heat warning.
If you have a chronic health condition or are taking medication, such as antidepressants, sleeping pills, diuretics, diabetes medication, antipsychotics, and the like, you should talk to your doctor or a healthcare professional about what to do when it gets very hot.
If you are vulnerable to heat, or if you know someone who is at risk, contact Info-Santé 811 for an assessment and recommendations, especially if you notice a deterioration in your health. Call 911 or go to the nearest hospital in case of a medical emergency.
Babies and children
During hot weather, babies and children can quickly become ill. Take certain precautions to improve their comfort and reduce health risks.
Keep your children well hydrated:
Make sure they drink water regularly and, if possible, provide them with a water bottle.
For breastfed babies, offer the breast on demand. It is perfectly normal for them to feed more often.
For babies fed with commercial infant formula, offer it more often.
For babies over six months old, offer small amounts of water after or between feedings.
Cool children down often, for example:
Give them a lukewarm bath or shower as often as necessary.
Moisten their skin with a wet towel several times a day.
Protect them from the heat:
Dress them in light clothing.
Cover their heads with a wide-brimmed hat.
Never leave them alone in a poorly ventilated room.
Limit their exposure to heat:
Limit their outdoor activities, such as endurance sports competitions.
Plan these activities before 10 a.m. and after 4 p.m., when the heat is less intense.
Limit or interrupt physical activity for children with acute or chronic illnesses.
For animals
Do not leave your pets in the sun and give them water so they can stay hydrated.
Check with your municipality to find out what measures are in place to mitigate the effects of extreme heat, such as opening or extending the hours of certain municipal services (e.g., swimming pools, water parks, air-conditioned facilities).
Guidelines and restrictions during extreme heat
Follow the guidelines when engaging in forest activities
Observe restrictions on access to forests and on traffic, work, or burning in forests during periods of high heat. Be wary of dry vegetation, including in your garden. Observe bans on open fires in forests or nearby, and find out about safety advice and instructions to follow in the event of a forest fire.
Observe watering restrictions during periods of drought
During periods of drought, watering restrictions may be imposed by local authorities to ensure the supply of drinking water for the entire population.