Working in Hot Weather

The summer season often brings hot temperatures and high humidity. When our bodies are exposed to these conditions, we usually react by sweating, which cools us off and regulates our body temperature. Normal body temperature is between 36°C and 38°C. If your body's temperature rises above normal, it can lead to heat stress, which is the body's inability to control its internal temperature. Symptoms of heat stress include the following:

  • excessive sweating, which causes the body to lose fluid and increases heart rate
  • heat illness: headaches; nausea; vomiting; dizziness
  • heat exhaustion: tired or weak; moist skin; rapid, weak pulse
  • heat stroke: hot, dry skin; rapid, strong pulse; mental confusion; unconsciousness; seizures or convulsions. Heat stroke can result in death.
Note: Prolonged sun exposure can lead to skin cancer.

Workers who are exposed to hot weather include construction workers, postal workers, street cleaners, conservation officers and others.

Employers' safety and health responsibilities related to hot weather


The Manitoba Workplace Safety and Health Regulation, Part 4.12 (Thermal stress) requires employers to:
  • implement safe work procedures and control measures based on the threshold limit values for thermal stress established by the American Council of Governmental Industrial Hygienists (ACGIH); and
  • provide workers with information, instruction and training in the symptoms of thermal stress and the precautions to be taken to avoid injury from thermal stress.

Ways to prevent heat stress

  • Wear light and loose-fitting clothing.
  • Work in workspaces with good ventilation (for indoor work).
  • Drink water when you're thirsty.
  • Take frequent breaks when working in the heat and rotate work tasks to avoid too much exposure to heat.
  • Work indoors instead of outdoors, if possible.
  • Use shades and sunscreen.

Employers should anticipate whether their workers will be exposed to hot weather environments, and create hot weather safe work procedures in consultation with the safety and health committee, the worker representative, or if there is no safety and health committee or representative, with the workers themselves.

​Check out our Shop Talk and safe work procedure template for working in hot weather. Below the FAQs ​are more resources related to working in hot weather.

Shop Talk: Hot Weather      Safe Work Procedure Template: Lawn Mowing (Push) in Hot Weather



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