Santé Montréal


click on the picture to enlargeWho is most vulnerable to heat?

  • Older people (aged 65 and over)
  • People with chronic diseases
  • People with mental health problems (especially schizophrenia and alcohol or drug addiction)
  • Children 0 to 4 years old are also vulnerable to heat.

What can you do to help people vulnerable to heat?

  • Check in on them regularly.
  • Make sure they are following prevention advice and offer to find them help, if needed.
  • Make sure they can spend time in a cool or air-conditioned place.

How can you prevent heat-related health problems? 

  • Drink a lot of water, even before you feel thirsty.
  • Spend 2 to 3 hours a day in a cool, preferably air-conditioned place.
  • Take at least 1 cool shower or bath a day, or cool your skin with a wet washcloth several times a day.
  • Reduce physical effort.

To find out more, see the information sheet It’s really hot! (PDF).

Children 0 to 4 years old

To find out about precautions to take, see the documentation (PDF).

What are the symptoms to watch for?

  • Exhaustion (fatigue)
  • Dehydration (dry mouth)
  • Headaches
  • Dizziness
  • Confusion
  • Fainting 

If these symptoms are present, call Info-Santé at 811 or consult a health professional. 

If there is fever in addition to those symptoms, this may be heatstroke, which is a medical emergency. In this case, call 9-1-1 to get help. 

  • See the map of refreshment points and air-conditioned public places in the City of Montreal.


What's the difference?

Oppressive heat 

  • The temperature reaches 30 °C with a Humidex of 40 or more.
  • Environment Canada issues a warning.
  • The main effect of heat on the population is discomfort. 

Extreme heat

  • Three consecutive days or more when the average temperature reaches 33 °C during the day and doesn’t drop below 20 °C at night


  • The temperature doesn’t drop below 25 °C for two consecutive nights.
  • Extreme heat can cause vulnerable people’s health to deteriorate rapidly and can even lead to death.