Cold Stress

Kwantlen Polytechnic University (KPU) has established the following cold stress guidelines to protect the health of the university students, faculty, and employees. The goal of the cold stress guidelines is to minimize the detrimental effects of cold related illnesses on KPU employees who are required to work in cold environments.  

What is Cold Stress?

Cold stress can occur when a person is exposed to low temperatures, brisk winds, or wet environments. Under these conditions the body can lose heat rapidly and serious cold related illness and injuries, permanent tissue damage, and death may occur. Hypothermia, frostbite, and trench foot are examples of cold related illness.

Causes of Cold Stress

Workers can be exposed to cold stress when the following five main conditions are present:

  • Naturally or artificially cooled environments,
  • Wind that pulls heat away from body in any environment,
  • Wet clothing from sweat or water,
  • Cold water immersion, which cools the body 25 times faster than cold air, and
  • Fatigue, which makes it harder for the body to generate heat.

Wind Chill

The severity of heat loss is dependent on temperature and wind. This is known as wind chill. The following is an example of wind chill:

  • Your skin can freeze in about a minute at an air temperature of - 30ºC with a wind speed of 16 km/h (e.g., strong enough to fully extend a flag).
  • Your skin can freeze in 30 seconds at an air temperature of - 30ºC with a wind speed of 48km/h. 

Wind chill can play a major role for the onset of cold stress illnesses because it speeds up the rate at which your body loses heat. Generally, your risk of frostbite and hypothermia with prolonged cold exposure without appropriate protection increases when wind chill values go below -27. It is important to keep an eye on the weather forecast to ensure adequate preparation for working in cold environments.

Click on the following for additional information on the wind chill index and work/warm up schedule for a 4-hour shift.

Signs and Symptoms of Cold Related Illnesses


You can experience hypothermia when your body begins to lose heat faster than it can produce, during exposure to cold environments. The onset of hypothermia is a gradual process and can be fatal if not acted upon. You may not realize you are in danger until it’s too late. Take notice when you are feeling cold as it is the most important warning sign.

The following are the three key stages of warning signs for hypothermia.




  • Shivering and complaining of cold
  • Grogginess
  • Poor Judgement or confused thinking




  • Violent Shivering
  • Inability to think or pay attention
  • Slow, shallow breathing
  • Slurred speech
  • Poor body coordination




  • Loss of Consciousness
  • Little or no breathing
  • Weak, irregular, or non-existent pulse


You can experience frostbite when cold exposure causes the freezing of outer and inner layers of the skin. Frostbite leads to a loss of feeling and colour disfiguration in extremities of the body (e.g., nose, ears, cheeks, chin, fingers, or toes). It can permanently damage body tissues and in severe cases can lead to amputation.  A person’s skin may appear shiny and rose is an early warning of frostbite. This is known as ‘frost nip’. It is important to move to a warmer environment or protect the skin with layers of clothing when this occurs.

Some common signs and symptoms of frostbite can include:

  • Numbness
  • Hardened skin
  • Tingling or stinging
  • Bluish or pail, waxy skin
  • Reduced blood flow to hands and feet

Trench Foot

Trench foot or immersion is a non-freezing injury of the feet. It is caused when you are exposed to prolonged wet and cold conditions.

The following are some signs and symptoms of trench foot:

  • Reddening and blistering of skin,
  • Tingling or numbness,
  • Pain or leg cramps, and
  • Swelling.

General Guidance for Preventing Cold Stress

You can use the following guidelines to prevent the effects of cold stress:

  • Take frequent short breaks in warm dry shelters.
  • Schedule outdoor work to warmest hours of the day and minimize activities that reduce circulation.
  • Learn the signs and symptoms of cold-induced illnesses/injuries and how to treat them.
  • Monitor wind chill and weather warnings to ensure you are prepared for work outdoors.
  • Wear warm head covering.
  • Use a buddy system (work in pairs).
  • Select clothing appropriate for cold, wet and windy conditions. Layer clothing and avoid wearing tight fitting clothing.
  • Have extra clothing available.
  • Avoid exhaustion or fatigue because energy is needed to keep muscles warm.
  • Stay hydrated.
  • Drink warm, sweet beverages (e.g., sugar water, sports-type drinks). Avoid caffeine or alcohol.
  • Protect vulnerable areas such as fingers, toes, ears and nose (e.g., use protective gloves, mittens, footwear, head covering or facemask).
  • Wear eye protection, if work takes places outdoors in snow- or ice-covered terrain with excessive ultraviolet, glare, or blowing ice crystals that present a risk of injury to the eyes.
  • Avoid skin contact with surfaces colder than -7°C (19.4°F).

What if Someone is Feeling ill From Cold Exposure?

Signs of progression to moderate or severe hypothermia should be considered a medical emergency where 9-1-1 must be called and first aid is notified. For all other cold stress injuries, the individual can be moved to a warm environment and first aid is called.

The items below highlight basic first aid steps individuals can take to assist injured persons.

Hypothermia First Aid

  1. Move person to a warm place
  2. Remove wet clothing
  3. Warm center of body first (e.g., chest, head, neck and groin).
  4. Give warm beverages if individual is conscious.
  5. Wrap body and head in a warm blanket.
  6. Administer CPR if unconscious.

Frostbite First Aid

  1. Move into a warm dry area and keep affected areas warm to prevent re-freezing.
  2. Get medical aid as soon as possible.
  3. Remove any wet or tight clothing.
  4. Warm the area with body heat. Do not rub the frostbitten area this could cause tissue damage. 
  5. Do not thaw hands and feet unless medical aid is far away and there is no chance of refreezing. It is best to thaw body parts at a hospital.

Trench Foot First Aid

  1. Remove wet shoes, boots, and socks.
  2. Dry feet and avoid working on them.
  3. Keep affected feet elevated and avoid walking.
  4. Get medical attention.

Additional Support, Resources, and References