Extreme cold weather occurs when low temperatures from -15° Celsius to -25° Celsius combine with winds blowing at 30 to 50 km /hour, with gusts to 60 km/hour.
That combination of cold and wind is called wind chill, and it can cause the temperatures people actually experience to drop to between -35° Celsius and -50° Celsius in certain regions of Québec.
Some people are especially vulnerable to extreme cold. They are: the homeless, the elderly, people with reduced mobility and anyone who has a heart problem or asthma.
Extreme temperatures can also be dangerous for people who are heedless of the danger, like children, overconfident athletes and people suffering from a psychiatric disorder.
Any prolonged outdoor exposure can be dangerous for a person whose vehicle has broken down or who is working outside.
- Any outdoor activity, even a short walk, that exposes a person to the wind creates a potentially hazardous situation in extreme cold conditions. The risk depends on the length of the exposure and the level of activity (the less active you are, the higher your risk is).
- Conditions that increase exposure to the wind also increase the danger (open terrain, high ground, greater speed, etc.).
- People involved in a vehicle breakdown or in a solitary or unsupervised outdoor activity are vulnerable.
- Electrical or gas burning devices not designed to be used as auxiliary heaters (box stoves, briquettes, gas or kerosene burners) create an indirect but real hazard.
- Alcohol and certain blood pressure or heart medications (vasodilators) can increase the health risk.
- Going outside in damp clothes or with exposed wet skin or hair is a recipe for trouble.
- Anyone who is vulnerable (and especially children and people with heart conditions or asthma) should avoid going out.
- If you do have to go out:
- cover yourself completely, and particularly your head, because you can lose up to 30% of your body heat through your head;
- cover your extremities, including your nose and ears; to keep your body heat, avoid uncovering your hands even briefly and dress very warmly; and
- protect your face from the cold by putting on sun cream and breathing through a scarf; anyone who is exposed to cold needs to keep moving and keep the wind at their back as much as possible.
- Avoid long-distance road trips unless your vehicle is reliable and you have an adequate supply of fuel, windshield washer fluid, etc. Always take along warm clothes, candles and matches and a cell phone, and remember to tell people you know when you are leaving and when you have arrived.
- If you are driving in the city, be doubly careful of pedestrians, who often have their view obstructed by hoods, hats or scarves and by the bitterly cold wind. Slow down before you arrive at intersections and look both ways before proceeding.
- Do not go outdoors alone in an isolated or unsupervised place.
- Dry yourself off thoroughly after showering if you are planning to go outdoors.
- Avoid drinking alcohol outdoors or before going out. If you work outside, make sure that you go into a heated shelter regularly to avoid frostbite.
- At home, check your heating systems and your smoke detectors to ensure that they are functioning properly, keep a close eye on your auxiliary heaters and never use a heating appliance designed solely for outdoor use (barbecues, camping stoves or burners, etc.).
The effects on the body
The effects of cold are insidious because cold causes a loss of local sensation.
- If your skin is exposed, you run the risk of frostbite, because skin can freeze in as little as six to ten minutes.
- Exposure to extremely cold air makes your heart beat faster and causes you to breathe faster; breathing in cold air can irritate your airways.
- Hypothermia can set in, triggering a sensation of cold and unstoppable shivering. If the exposure continues, you will start to feel euphoric, intoxicated, disoriented and confused, after which you may fall into a coma and even die.
- Extreme cold can indirectly impact health due to increased risk of fire, carbon monoxide poisoning (CO is an odourless gas) and isolation.
See Environment Canada's Seven steps to cold weather safety
Whom should you contact to get help?
- If you get frostbite, you need to get into a warm place as quickly as possible. If you are outside, rub your ears and nose with your hands to warm them. Warm your hands by putting them inside your clothes, in your armpits or between your thighs. If their colour does not come back within a few minutes, your skin may start looking as if it had been burned as it warms, and you should see a doctor.
- Hypothermia is an emergency condition requiring the person to be wrapped in warm blankets and given hot liquids. Hypothermia can cause serious heart problems, so it is essential to get to a hospital immediately.
- If you have a breakdown on the road, call for help but do not set out on foot alone. You should stay in your vehicle, cover yourself warmly, light a candle and wait for help to arrive.