Heat stress can happen when hot, humid conditions and physical activity overcomes your body’s natural cooling system. You might suffer cramps and fainting, or even serious heat exhaustion and heat stroke. Heat stroke can kill quickly.

Our bodies naturally maintain a temperature between 36°C and 38°C. Sweating cools our bodies down, but if you work in a hot environment this might not be enough. If your body heats up faster than it can cool itself, you experience heat stress. This can lead to serious heat disorders and potential injury.

As a worker’s body heats up it loses fluids and salt through sweat. As workers dehydrate they are less able to cool themselves down. Workers in a hot environment should be aware of these warning signs of heat stress:

  • Excessive sweating
  • Dizziness
  • Nausea

According to the Employment and Labour Law website:

If there is a risk of excess heat exposure in the workplace, an employer is well-advised to take the following steps to prevent heat stress:

  • Train supervisors and workers to recognize early signs and symptoms of heat stress in themselves and their co-workers, including excessive sweating, dizziness and nausea
  • Where working in hot environments, arrange work schedules to permit employees to become acclimatized to heat
  • Provide adequate supervision and don’t allow individuals to work alone in conditions where heat stress is a legitimate risk
  • Determine appropriate work-rest cycles that allow time for workers to cool down
  • Provide shaded or well-ventilated areas for breaks and rests and, where appropriate, reduce temperature and humidity through air conditioning
  • Schedule more physically demanding work at cooler times of the day and, where possible, rotate work activities to reduce heat exposure
  • Make cool drinking water available and remind workers to drink water regularly to stay hydrated (i.e. approximately 250 mL of water every 20 minutes)
  • When working outdoors, remind workers to wear light-coloured, loose-fitting clothing that is breathable
  • Encourage workers to wear long-sleeved shirts and pants and keep their heads covered to reduce direct exposure to the sun when working outdoors
  • If you suspect that a worker is suffering from heat stress, move him or her to a cool, shaded area, provide the worker with water and appropriate first aid

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

The most effective way to reduce the risk of heat stress is to eliminate the source of exposure.


Preventing Heat Stress In The Workplace