Temperature Conditions – Cold Fact Sheet

IS THERE A MINIMUM TEMPERATURE AT WHICH WORK BECOMES DANGEROUS AND SHOULD BE STOPPED?

The short answer is yes.

At very cold temperatures, the most serious concern is the risk of hypothermia or dangerous overcooling of the body. Another serious effect of cold exposure is frostbite or freezing of the exposed extremities such as fingers, toes, nose and ear lobes. Hypothermia could be fatal in absence of immediate medical attention.

What are the warning signs of hypothermia?

Warning signs of hypothermia can include complaints of nausea, fatigue, dizziness, irritability or euphoria. Workers can also experience pain in their extremities (hands, feet, ears, etc), and severe shivering. Workers should be moved to a heated shelter and seek medical advice when appropriate.

Are there exposure limits for working in cold environments when outdoors?

In Canada, the legislation from some jurisdictions provides a range of acceptable temperatures for specific circumstances. In other cases, occupational health and safety jurisdictions use the Threshold Limit Values® for cold stress as published by the American Conference of Governmental Industrial Hygienists (ACGIH). Some Canadian jurisdictions have adopted these TLVs as occupational exposure limits and others use them as guidelines.

Where there are no maximum/minimum exposure limits for cold working environments, there are guidelines that can be used to conduct work/task assessments, create safe work plans, and monitor conditions to protect the health and safety of workers who may be exposed to cold temperatures. Where there are differences between the recommendations made by various organizations (and where there are no established limits or guidelines from your jurisdiction), employers are encouraged to choose a system that best provides protection for their workforce.

If signs of cold stress are noticed, return to the shelter immediately. For work at or below -12°C (10.4°F), work should include:

constant observation (supervisor or buddy system),
adjusting the pace or rate of work so that it is not too high and cause heavy sweating that will result in wet clothing
time for new employees to become accustomed to the conditions
adjusted to include the weight and bulkiness of the clothing when estimating work performance and weights to be lifted by the worker
arranged in such a way that sitting and standing for long periods is minimized
instructions in safe work practices, re-warming procedures, proper clothing practices, proper eating and drinking habits, recognition of cold stress/frostbite, and signs and symptoms of hypothermia or excessive cooling of the body (including when shivering does not occur)

What are exposure limits for working in the cold when in a building or indoors?

Some Canadian jurisdictions specify a minimum temperature for indoor work environments in buildings that are normally heated.

What should be done when it is very cold or windy outside?

Employers have a duty to take every reasonable precaution to make sure the workplace is safe for the worker. This duty includes taking effective measures to protect workers from cold stress disorders if it is not reasonably practicable to control indoor conditions adequately, or when the work is done outdoors.

General recommendations include to:

Dress in layers of warm clothing, with an outer layer that is wind-resistant.
Cover all exposed skin.
Wear a hat, mittens or insulated gloves, a scarf, neck tube or face mask, and insulated, waterproof footwear.
Stay dry (including taking steps to prevent excess sweating).
Keep active.
Maintain a work/break schedule. Breaks should be taken in a warm area, with protection from drafts.
When very cold, consider cancelling outdoor activities.