Heat stroke prevention

by May 2, 2019General

Warning: summer is coming soon!

In Quebec, cool weather quickly gives way to summer heat. It is not uncommon to have a first heat wave at the beginning of June. This meteorological phenomenon leads to hot thermal stress “heat stroke” in many workers, because their bodies are not yet used to a warm environment.

Preventing heat stroke is critical. If it is not treated quickly, it can have severe effects on a worker’s central nervous system that can even lead to death.

On average, a worker dies from heat stroke every year. In addition, the discomfort related to working in a hot environment can be felt for several days making workers unfit to perform their regular tasks.

Prevention through work organization

You must be ready before the onset of extreme heat waves by targeting tasks that require more physical effort, tasks that are performed outdoors or in a place where the temperature will be high, with little or no air flow. Once this exercise is performed, the following preventive measures can be put in place:

  • Monitor your workstations with a standard WBGT or thermometer
    • In order to correctly interpret your readings, refer to Schedule V of the RSST.
  • Install fixed fans or have portable fans available
  • Schedule more frequent breaks according to Schedule V of the RROHS
    • The IRSST has developed software to help you
  • Take breaks in an air-conditioned or cool place
  • Offer refreshments (popsicles, cold water) during these breaks
  • Schedule a staff rotation
  • Plan harder/more intense jobs early in the morning or evening

Prevention through lifestyle

During heat waves, the body dehydrates quickly. It is important to drink water before feeling thirsty. The CNESST recommends that workers drink a glass of water every 20 minutes. Know that the caffeine contained in coffee or energy drinks are diuretics that accelerate dehydration. They should not be consumed by workers exposed to heat.


Prevention through training and awareness

Victims of heat stroke are not aware of what is happening to them. For this reason, we must mind ourselves but also our colleagues. The faster the intervention, the more effective it will be. Knowing how to recognize the signs and symptoms of heat stroke can really save lives.

Here are the first signs of heat stroke:

  • Irritability
  • Marked fatigue
  • Headache
  • Abundant perspiration
  • Nausea
  • Dizziness
  • Thirst
  • Difficulty concentrating
  • Facial skin becomes reddish


First aid:

It is critical to stop all physical activities when the first signs of heat stroke appear, as the heat stored in the upper and lower limbs will tend to travel to the head. The pituitary gland can be disrupted, and body temperature will continue to increase. You must bring the person to a cool place, apply a cold wet towel or a bag of instant ice at the nape of the neck and armpits to reduce body temperature. Never leave the victim alone and make sure that they drink small amounts of water, but often. It is strongly recommended that the worker be seen by a doctor.

  • Even if the victim tells you that they feel better, do not return them to their workstation on the same day. Their body is already tested and weak, they are much more likely to see their symptoms reappear.



Here are the symptoms of severe heat stroke:

  • Vomiting
  • Loss of consciousness
  • Very pale (grayish) facial skin
  • Confusion
  • Abnormal aggression
  • Delirium
  • Rapid and weak pulse
  • Rapid breathing
  • Red, hot and dry skin
  • Loss of consciousness
  • Seizures
  • Fever above 40 ° C

First aid:

This is a medical emergency, contact 911 as soon as possible.

If you can not move the victim, wet their clothes with cold water while waiting for help.


Summer is so long awaited for all its benefits. Make sure you have a good heat stroke prevention program to make the most of your vacation and long sunny days!


If you need help, do not hesitate to contact our experts.

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Intervention Prévention Inc.

Intervention Prévention concentrates its operations in the field of work safety, offering specialized services following Standards CSA Z462 – Workplace Electrical Safety, CSA Z460 – Control of Hazardous Energy: Lock-out and Other Methods, and CSA Z432 – Safeguarding of Machinery.


226-3275 rue de l’Industrie
Saint-Mathieu-de-Beloeil (Québec)
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