Health & Safety
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Understanding your safety role at UBC
The Centre for Occupational Health, Safety, and Wellbeing
Occupational Hygiene
Laboratory Safety
Safety & Advisory Committees
Safety Programs
Student Safety
Health & Safety View
UBC Safe Vancouver app
Understanding your safety role at UBC
The Centre for Occupational Health, Safety, and Wellbeing
Occupational Hygiene
Laboratory Safety
Safety & Advisory Committees
Safety Programs
Student Safety

Thermal stress safety

Heat stress and safety

Working in hot environments, outdoors or indoors, can affect the body’s cooling system. If the body is unable to cool itself, then a rise in body temperature can result in stress. If not recognized and addressed early, this can quickly develop into more serious and life-threatening conditions. Physical exertion, environmental factors, and physiological conditions are all factors contributing to heat stress and must be considered when evaluating exposure risk.

Signs and symptoms of heat stress

As the body heats up it loses fluids and salt through sweat. As dehydration develops, the body is less able to cool itself down. The signs and symptoms of heat stress can vary depending on severity and individual health, but most commonly includes

  • Excessive sweating
  • Dizziness
  • Nausea

If heat stress is not recognized and treated early, it can lead to heat disorders, which have serious effects on the body.

Preventing and minimizing heat stress and exposures

Training

Heat Stress Awareness (online) – This course discusses risk factors for individuals potentially exposed to heat, the associated heat stress disorders, and control measures to protect against heat stress.

General guidance

Review the hierarchy of controls

  • Schedule tasks to cooler days, times (typically before 11 a.m.) or move to cooler environments.
  • Modify work practices and procedures to mitigate the risk.
  • Make physical modifications to facilities, equipment, processes to reduce exposure, while considering the potential requirement for engineering approval.
  • Establish cooling areas with shade and water.
  • Gradually increase workload in hot environments to allow for acclimation.
  • Plan and implement appropriate work-rest cycles; when a worker feels ill it may be too late.
  • Rotate work activities or share the load across additional workers to reduce individual exposure.
  • Drink plenty of water.
  • Take rest breaks in a cool, well-ventilated area.
  • Wear light-coloured, loose-fitting clothing made of breathable fabric, such as cotton.

General outdoor guidance

  • Protect yourself from the sun by staying in the shade, avoiding direct sun mid-day, wearing a hat and protective clothing, using sunscreen, and wearing UV-protective eyewear.
  • Seek cooler, breezier areas when outdoors, such as large spaces with lots of trees.
  • Stay hydrated by drinking water regularly, even more than you think you need.
  • Take it slow with outdoor activities, rest often.
  • Check in regularly with individuals to assess well-being.

General indoor guidance

  • Close blinds and shutters during the daytime and open them at night if the space is occupied. Open windows at night to let in cooler air if the space is occupied.
    • Note: blinds, shutters and windows should always be closed if the space is not occupied to mitigate security risks
  • Make use of air conditioning, if available.
  • Mist yourself and your clothing with cool water to keep from overheating.
  • Stay hydrated by drinking water regularly, even when not thirsty.

Assessments

If you need assistance in determining ongoing heat exposure risks and evaluating the controls in place, please contact Safety & Risk Services.

What if someone is feeling ill from heat exposure?

If an individual exposed to heat shows signs or reports symptoms of heat stress or injury, the individual must be removed from further exposure and treated by an appropriate first aid attendant or a physician.

If heat stroke or other severe heat related illnesses are suspected, call 911 immediately then first aid.  

Cooling centres on the UBC Vancouver campus

The following UBC buildings have air conditioning and are open to the public. See hours of operation below:

Be sure you’re ready for an extreme heat event.

Additional support, resources, and references

Cold stress and safety

Cold stress can affect individuals working in cold or wet environments. Severe cold stress can lead to hypothermia, which can be fatal. Cold stress can result from:

  • Naturally or artificially cooled environments
  • Wind, which draws heat away from the body
  • Wet clothing, from sweat or water
  • Cold water immersion
  • Fatigue, which makes it difficult for the body to generate heat

Signs and symptoms of cold stress

When exposed to cold, the body responds by constricting blood flow to the skin to limit heat loss and by shivering to increase heat production. The signs and symptoms of this include: 

  • Pain, stinging or numbness of hands, feet, nose, cheeks, or ears 
  • Whitening of fingers and/or toes 
  • Leg cramps 
  • Loss of dexterity 
  • Shivering 
  • Confusion 
  • Loss of coordination 

Cold stress can result in several health effects. Most cold related illnesses develop gradually and workers may not realize they are in danger until it is too late. Feeling cold is an important warning sign. If workers feel cold then their bodies are likely losing heat too quickly and controls need to be implemented. 

Preventing cold stress and exposures

Training

Cold Stress Awareness (online) – This course discusses the risk factors for individuals exposed to cold, the associated cold stress disorders, and control measures to protect against cold stress.

General guidance

  • Monitor cold conditions and advise workers to avoid working alone. Working in pairs, prevent cold-related illness from occurring if co-workers monitor one another for the signs and symptoms of the illness.
  • Review risk assessments and specific safe work procedures, and adjust as necessary.
  • Ensure there is adequate first-aid coverage and emergency procedures are in place.
  • Be aware of and check the signs and symptoms of cold stress for yourself and co-workers.

Review of hierarchy of controls

  • Schedule tasks for warmer days, times or environments.
  • Modify work practices and procedures to limit the risk.
  • Make physical modifications to facilities, equipment, and processes to reduce exposure while considering the potential requirement for engineering approval.
  • Establish heated warming areas/shelters/vehicle cabs.
  • Plan and implement appropriate work-warm up schedules; when a worker feels ill it may be too late.
  • Rotate work activities or use additional workers to reduce exposure.
  • Complete a warm-up prior to working to prepare joints and muscles.
  • Wear a warm head covering and layered clothing, and keep hands and feet warm and dry.
  • Consider the need for survival kits.

Assessments

If you need assistance in determining ongoing cold exposure risks and evaluating the controls in place, please contact Safety & Risk Services.

What if someone is feeling ill from cold exposure?

If a worker exposed to cold shows signs or reports symptoms of cold stress or injury, the worker must be removed from further exposure and treated by an appropriate first aid attendant or a physician.

If hypothermia or other severe cold related illnesses are suspected, call 911 immediately then first aid.

Additional support, resources and references

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