Extreme Heat

Protect Yourself during Heat Waves

Extreme heat can have health impacts, especially dehydration, significant fatigue, headache, nausea, and dizziness. Avoid heat's harmful effects:
  1. STAY HYDRATED: Drink plenty of fluids (e.g., water, juice diluted with water, sports drinks without caffeine) without waiting to feel thirsty or as recommended by a doctor.
  2. KEEP COOL: Spend at least 2 hours a day somewhere cool (ideally with air-conditioning).
  3. LIMIT PHYSICAL ACTIVITY: From 10 a.m. until the evening, avoid strenuous physical activity outdoors.

At-Risk individuals

The following people are at greater risk of developing complications if exposed to heat:

  • babies and children under 5;
  • the elderly
  • people with reduced autonomy or who live alone;
    • people with reduced mobility;
    • people who have limited contact with their friends and family; 
  • people with chronic illnesses or serious mental health problems;
  • people with alcohol or drug abuse problems; 
  • people who work in physically demanding jobs or in the sun or outdoors; for example, construction and agricultural workers;
  • people who work in environments where work processes generate heat, such as foundries or bakeries;
  • people who exercise intensely outdoors in hot weather, or indoors in non-air-conditioned or poorly ventilated premises;
  • people who do not have access to cool or air-conditioned areas;
  • people taking certain prescription medications that may aggravate the effects of heat;
  • people in poor physical condition or who are overweight;
  • people who are ill with fever;
  • pregnant women and their fetuses.

At-Risk Areas – Heat Islands

Certain environmental features increase heat-related health risks. For example, urban areas with a significant amount of asphalted surfaces, certain types of buildings, and scant vegetation can create what is known as the "urban heat-island effect." Heat islands can be up to 12°C hotter than other areas in the same region. There is a high concentration of urban heat islands in the various municipalities in Estrie.

If you live in an urban heat island, you are at greater risk of having heat-related issues.

Locate heat islands in Estrie. Vulnerable areas are identified in two sources:

Specific recommendations - Indoors

Recent evidence shows that maintaining an indoor temperature of 31 °C or more is dangerous for elderly persons, those with chronic diseases, and those with significant mental health disorders.
How do you lower indoor temperature? 

In preparation for a heat wave: 

  • Install thermal curtains, roller shutters, or solar window films to block heat and sunlight. 

During a heat wave: 

  • Keep curtains and blinds shut from 10 a.m. to 8:00 p.m. to block sunlight.
  • Keep windows closed from 10:00 a.m. to 8:00 p.m. to trap cool air inside.
  • Open the windows at 8:00 p.m. to allow cool air to flow in, and use fans to circulate the air indoors.

Is a fan effective at helping you cool down? 

When the indoor temperature is very elevated, for an elderly person, a fan will be only minimally effective at lowering body temperature and at preventing heat-related health problems. It is recommended not to use fans as the main method to cool down when indoor temperatures are constantly at 31°C or above. 
What if it’s too hot in my home?

  • Use a digital thermometer inside your home to identify its coolest rooms (< 31°C). 
  • If there are no sufficiently cool rooms in your home, identify a place where you can go (e.g., to the home of a loved one) during the heat wave, especially if you are aged 65 or older or have a chronic disease or have a major mental health disorder.

Useful Links

Are you a municipal or community actor?

Consult the intervention toolbox (French)