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Working outdoors? The rules for employers and the signs and symptoms of cold stress

With a deep freeze hitting much of Canada this week, being out in the cold for merely a few minutes could be damaging to your body. What about those who spend their working days outdoors? They may be acclimatized to the cold, but there are limits. In this post, we explore existing standards and regulations in Canada and help you recognize the signs that you or your co-workers could be at a high risk for hypothermia or frostbite.

Are there rules in Canada around exposure to cold temperatures for the workplace?

There are no maximum exposure limits for cold working environments in Canada (though there are established standards) and most jurisdictions do not have specific measures that must be complied with under the law. However, this generally falls under the occupational health and safety requirement for employers to ensure the health and safety of workers.

In addition to federal regulations around equipment being used outdoors, Saskatchewan, Manitoba, New Brunswick, Nova Scotia, Prince Edward Island, Newfoundland and Labrador, and Yukon specifically mandate measures employers must take to minimize the impacts of the extreme cold.

In Saskatchewan those measures must include frequent monitoring of thermal conditions, providing screens, shelters and temporary heating equipment, suitable clothing or personal protective equipment, using acclimatization or other physiological procedures, limited work schedules with rest and recovery periods, changes in workloads, changes in hours or other arrangements for work, as well as frequent observation of workers by a person who is trained to recognize the symptoms of physiological stress.

What are the health problems caused by exposure and how do you recognize the signs/symptoms?

The health effects of exposure to cold include:

  • Frostnip: The mildest form of a freezing cold injury, occurs when ear lobes, noses, cheeks, fingers, or toes are exposed to the cold and the top layers of the skin freeze.
  • Frostbite: Caused by exposure to extreme cold or by contact with extremely cold objects. Frostbite occurs when tissue temperature falls below freezing (0°C), or when blood flow is obstructed by the cold. Blood vessels may be severely and permanently damaged. Frostbitten skin is also highly susceptible to infection and gangrene.
  • Hypothermia: Occurs when the body is unable to compensate for its heat loss and the body’s core temperature starts to fall.
  • Chilblains: A mild cold injury caused by prolonged and repeated exposure for several hours to air temperatures from the freezing point (0°C) to as high as 16°C.
  • Immersion Foot: Occurs in individuals whose feet have been wet, but not freezing cold, for days or weeks. The primary injury is to nerve and muscle tissue.
  • Trenchfoot (or hand): This is also referred to as “wet cold disease” and results from prolonged exposure in a damp or wet environment from the freezing point to about 10°C.

The warning signs of cold stress include (from early stages to late stages):

  • Physical discomfort (feeling cold)
  • Possible injuries such as pulled muscles
  • Loss of feeling and dexterity in fingers, hands and toes
  • Frost nip (outermost layers of skin turn white)
  • Extreme discomfort
  • Extreme shivering (core temperature down to 35ºC), and then shivering stops
  • Loss of consciousness (core temperature 30ºC)
  • Mental changes – loss of alertness, slurred speech, fatigue, lethargy or apathy

Recognizing the signs and symptoms early on will help keep you and your co-workers healthy and safe! For more information on how to protect your employees from injuries caused by the cold, check out OSHA’s work/warm-up schedule and Health Canada’s tips on reducing the risks.

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Worksafe Alberta, Alberta Government. Best Practice – Working Safely in the Heat and Cold; July 2014. Available online:

Canadian Centre for Occupational Health and Safety. Cold Environments – Working in the Cold. Available online: