January and February: the heart of the winter season. While some people eagerly await the cold weather for activities like skiing, snowboarding, ice skating, and ice fishing, not everyone is so eager for these cold temperatures. In Canada, there are no maximum legal exposure limits for cold working environments. Not all workers can escape the cold blasts of "old man winter", but there are steps employers and workers can take to protect themselves from exposure to cold temperatures. Moreover, legal general duty clauses may also require employers to take every reasonable precaution to protect workers from the cold.

Injuries and illnesses that may be caused by extreme cold and wet weather conditions include hypothermia, frostbite, trench foot and chilblains. Every year many employers conduct safety talks with their workers to discuss appropriate clothing and work breaks when temperatures bottom out. However, it is also important to discuss symptoms of cold stress to help workers be proactive in preventing the onset of late symptoms of cold stress, which could result in critical injuries or death.

Cold-related injuries or illnesses that may occur due to overexposure to cold temperatures may include the following:

Hypothermia is a condition in which the body uses up all its stored energy and can no longer produce heat. Early symptoms to be aware of are shivering, fatigue, loss of coordination and/or confusion/disorientation. Basically the body is shutting down and brain function is affected negatively. Later symptoms of hypothermia include no shivering, blue skin, dilated pupils, a slowed pulse and slowed breathing, and/or loss of consciousness.

Frostbite is a condition where part of the body has experienced freezing such as the nose, ears, fingers or toes. Symptoms include a loss of feeling, numbness, aching, or tingling.

Trench foot is a condition to the feet in which they have been exposed to wet and cold conditions. Symptoms include reddening of the skin, numbness, leg cramps, swelling, tingling, blisters, bleeding under the skin and/or gangrene.

Chilblains are ulcers formed by damaged small blood vessels in the skin caused by continued exposure to cold temperatures. Symptoms include redness, itching, blistering, inflammation and/or possible ulceration.

Employers should also communicate the first aid requirements should workers become overexposed to cold temperatures. Emergency procedures and how to obtain medical care should be clearly understood by each shift and each crew; preferably posted for easy access.

The American Conference of Governmental Industrial Hygienists (ACGIH) developed the Work/Warm-up Schedule for a 4-hour shift that takes into account both air temperature and wind speed, and provides recommendations for work breaks and stopping non-emergency work. This best practice is one way to protect workers and ensure legal compliance. A copy of this schedule can be found here.

Understanding the symptoms of typical cold weather injuries or illnesses, together with proper cold weather clothing and appropriate breaks, will assist workers in protecting themselves from cold stress injuries and illnesses.