Heat Stress

Beat the Heat: Preventing Heat Stress

We all look forward to the sunny warm weather that comes with summer; however, high temperatures can pose a risk to workers, particularly for those whose jobs involve outdoor activities.  When heat is combined with other stresses such as high humidity, physical exertion, fatigue, or lack of acclimatization, it can lead to heat-related illnesses.  

The heating and cooling balance in our body depends on the amount of heat absorbed from the environment as well as the heat generated through physical activities.  As our body heats up, it tries to cool itself through the evaporation of sweat.  If body fluids and salts are not replaced, the body starts to overheat.  Heat-related conditions include heat rash, fainting, heat cramps, heat exhaustion and heat stroke. Depending on the condition, symptoms may include dizziness or fainting, nausea, weakness, heavy sweating, and rapid breathing. 

Report heat stress concerns to your supervisor. If you experience symptoms of heat stress during extreme heat, move to a cool area, loosen your clothing, get cool water to drink, and get medical attention immediately.

Tips for Preventing Heat Stress:

  • Be aware of days involving high temperatures or high humidity levels, particularly if you work outdoors.  The City of Toronto issues heat alerts during such conditions. 
  • Keep your body hydrated. Drink more water during hot days.
  • Wear breathable, light clothing that allows free movement of air. Air movement over the skin surface maximizes body heat removal by both evaporation and convection.
  • Schedule more strenuous activities during cooler times of the day.
  • Schedule frequent short breaks instead of a few longer breaks. Frequent short breaks away from the sun allow the body to cool down and prevent it from overheating.
  • Use sunscreen and keep your head covered.

If you work indoors and your work environment is at higher temperatures or humidity levels during the summer months, either because of mechanical failure or the lack of air-conditioning, inform your supervisor.  Facilities Management or Health and Safety Services can assist in assessing the situation.  Light clothing, hydration, fans, or breaks in a cooler environment can help reduce your discomfort.

For further information with regard to heat stress in the workplace, please visit: