Heat Waves

Topic Overview

A heat wave is 3 or more days in a row when the maximum temperature is 32°C (89.6°F) or more. Everyone has an increased risk for a heat-related illness during a heat wave. Extensive exposure to extreme heat can result in serious medical conditions such as heat cramps, heat exhaustion and heat stroke.

A heat-related illness can be more serious for:

    • Older adults, who may not notice excessive heat, do not sweat as effectively, or do not feel thirsty.
    • Small children, who can't transfer heat very well.
    • People with chronic medical conditions.
    • People taking medicines, such as heart medicines or tranquilizers, for serious psychiatric disorders or depression.
    • People with weight problems.
    • People with alcohol or drug use problems.
    • People with mental health or developmental problems.
    • People who work in the heat.
    • People who exercise in the heat.
    • People who are homeless. 

Other things that affect a person's risk for a heat-related illness during a heat wave include:

  • Living in cities, because heat is trapped by tall buildings and air pollutants.
  • Living alone.
  • Not having cooling devices, such as fans or air-conditioning.

Related Information


Adaptation Date: 7/24/2020

Adapted By: HealthLink BC

Adaptation Reviewed By: HealthLink BC

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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