Working in the Cold

Some jurisdictions provide a range of acceptable temperatures for working in the cold. Others use the Threshold Limit Values published by the American Conference of Governmental Industrial Hygienists (ACGIH) either as occupational exposure limits or as guidelines. Where there are no maximum exposure limits, the guidelines can help inform safe work plans to prevent cold stress injuries and illnesses.

Understanding the risk

When working in the cold, the toes, fingers, ears and nose are at greatest risk. Mental alertness is also reduced. Cold stress injuries and illnesses include:

• Chilblains – Symptoms include redness, swelling, blisters, tingling and pain.
• Immersion foot or trench foot due to prolonged wet or cold feet – Symptoms include tingling, numbness, itching, pain, swelling, and blisters.
• Frostnip – Occurs when the skin’s top layer freezes, turning white, numb and hard, but deeper tissue feels normal.
• Frostbite – Occurs when tissue temperature falls below the freezing point or from contact with cooled liquids. Symptoms include numbness, skin inflammation in patches and slight pain. Severe cases may cause tissue damage without pain, burning or prickling sensations, and blisters.

Hypothermia is the most severe cold stress illness. The excessive loss of body heat can be fatal. Symptoms may start with shivering, fatigue, loss of co-ordination and can progress to slow and shallow breathing, blue skin, and loss of reflexes. Move workers to a heated shelter and seek medical attention immediately.

Preventing cold stress injuries and illnesses

Employers should

• Choose equipment with thermal insulating materials and tools that can be operated with gloves.
• Train managers, supervisors and workers on symptoms, safe work practices, re-warming procedures, proper clothing practices, and what to do in case of cold stress.
• Encourage workers to watch for symptoms in others.
• Outline emergency procedures, with at least one trained person available at all times.
• Monitor temperatures and allow time for new workers to become accustomed to conditions.
• Adjust the pace or rate of work – not too low that a worker becomes cold or too high to cause heavy sweating or wet clothing.
• Wear personal protective equipment based on the work activity including
  • Layers of warm, loose-fitting clothing
  • A wind-resistant outer layer
  • A hat with ear protection, mittens or insulated gloves, scarf or face mask
  • Insulated waterproof footwear and wool socks