Santé Montréal

Extreme cold

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Description

An extreme cold event is defined as a period when temperatures drop dramatically below normal.

The wind can make temperatures feel even colder (wind chill); if it’s -15 °C outside and the wind is blowing at 35 km/h, the temperature feels like -27 °C.

In general, the effects on health increase when wind chill values fall below -27 °C.

People at risk

The people most vulnerable to extreme cold are:

  • Homeless people
  • The elderly
  • Infants
  • People with reduced mobility, and those with heart conditions, asthma or mental health problems

Extreme temperatures can also affect people who are oblivious to the hazards of cold, like some sport enthusiasts and people with mental disorders, dementia or Alzheimer’s. 

Risk factors

During periods of extreme cold, outdoor activities that expose people to the wind, including simply going from one place to another, can present risks. The longer someone is exposed, the greater the risk, for example, people whose car break down or those who work outdoors.

Factors that increase exposure to the wind (e.g. open areas, altitude and speed at which the person is moving) are also sources of danger.

Other situations that can present health risks in cold weather include:

  • Consuming alcohol
  • Taking certain medications for heart conditions or high blood pressure
  • Isolation
  • Wearing wet clothes or having damp hair or skin

Protection and prevention

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Symptoms

Frostbite

Frostbite causes the skin of the extremities (hands, feet, nose) to turn yellowish or white. Exposed skin can freeze in 5 to 10 minutes when the temperature is -35 °C and the weather is calm, or -30 °C and the wind is blowing at 15 km/h.

Irritation of the respiratory tract

Exposure to extreme cold and wind chill puts extra pressure on the heart and respiratory tract. More effort is needed to fight the cold, which can irritate the respiratory tract.

Hypothermia

When body temperature drops below 35 ºC, the body feels cold and starts to shiver. When someone is exposed to cold for an extended period of time, feelings of euphoria, disorientation and confusion can develop, and lead to coma or even death.

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When to Consult

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Complications

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Protection and prevention

People who are more vulnerable, especially children and people with asthma or heart conditions, should stay indoors.

If you must go out

  • Cover as much of your body as possible, including your head. You can lose up to 30% of body heat from the head.
  • Cover your nose, ears and other extremities. To preserve body heat, don’t uncover your hands, even for a few seconds, and dress very warmly.
  • To protect your face from the cold, put on a greasy lotion (sunscreen or Vaseline)  and wear a scarf. 
  • Don’t go out alone in remote areas or places that aren’t monitored.

Outside

  • When exposed to cold, keep moving and keep your back to the wind as much you can.
  • Don’t drink alcohol outdoors or before going out.
  • If you work outdoors, go inside regularly to warm up and to avoid frostbite.

Traveling by car 

  • Avoid taking long trips and make sure your car is reliable, the gas tank is full, the windshield washer fluid is topped up, etc.
  • Take warm clothes, candles and matches, and a cell phone with you.
  • Let someone know at what time you plan on leaving and when you think you’ll be arriving.
  • When driving, be very careful of pedestrians, whose vision is often partially obstructed by clothing, trying to prtotect temselves from the wind. Slow down before you get to an intersection and look both ways.

At home

  • Make sure your heating system and smoke detectors are working properly.
  • Use of space heaters that run on electricity or burnable fuel (wood or coal, briquettes, gas or oil) present a hazard because they can cause fires and emit carbon monoxide, a toxic odourless gas.

Se also, Environment Canada’s Seven Steps to Cold Weather Safety.

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Risk factors

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Help and Resources

Frostbite

If you get frostbite, you need to get into a warm place as quickly as possible.

If you are outside, warm your ears and nose with your hands. Warm your hands by putting them inside your clothes, underyour 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

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.

Breakdown on the road

If your car breaks down on the road, call for help but do not set out on foot alone.

You should stay in your vehicle, cover yourself warmly, turn the engine off, light a candle and wait for help to arrive.

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Treatment

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People at Risk

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Dernière mise à jour le : 2018.02.01