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Extreme heat


Extreme heat can be very dangerous. Know how to protect your health and that of your neighbours, friends and family.

Health effects of heat


Read the health effects of heat and ways to reduce exposure.

Click the image to view and download the poster. 


Extreme heat events, also know as "heat waves," can cause both heat exhaustion (less severe) and heat stroke (very severe), and can lead to an increase in deaths among Lower Mainland residents.

Signs of heat exhaustion include:

  • Heavy Sweating
  • Dizziness or Fainting
  • Nausea or Vomiting
  • Rapid Breathing & Heartbeat
  • Headache
  • Difficulty Concentrating
  • Muscle Cramps
  • Extreme Thirst
  • Skin Rash
  • Dark Urine & Decreased Urination 

Anyone with these symptoms should move to a cool space, drink plenty of water, rest, and use water to cool their body. 

Signs of heat stroke include:

  • High Body Temperature
  • Dizziness or Fainting
  • Confusion
  • Lack of Coordination
  • Very Hot and Red Skin

Heat stroke is a medical emergency. Seek medical attention immediately at an emergency room or urgent care centre. Call 911 if necessary. While waiting for help, cool the person right away by moving them to a cool place if you can, and apply cold water to large areas of the skin. 

People at higher risk

Different people respond differently to heat, and some people are at higher risk of experiencing health effects. Staying cool is especially important for the following groups of people:

  • People  over 65
  • People who are socially isolated and/or live alone 
  • People with multiple health conditions, especially comorbid diabetes
  • People with mental illness
  • People who live with addictions and substance use 
  • People who are marginally housed
  • People who work in hot environments
  • People who are pregnant
  • Infants and young children

Other people can be affected by heat too. Everyone responds differently, so listen to your body. 

Protect yourself from heat

Spending time in a cool space and drinking plenty of water is the best way to prevent heat-related illnesses

  • Seek cooler indoor and outdoor spaces (i.e. a local community center, library or mall)
  • Use water to cool off by taking a cool shower or putting a part of your body in a cool bath
  • Wear a wet shirt or apply damp towels to your skin to cool down
  • Drink plenty of water and other liquids to stay hydrated
  • Wear loose fitting and light-coloured breathable clothing
  • Limit activity, especially during the hottest hours of the day (generally 2 p.m. to 4 p.m. in B.C.)
  • Close windows and pull indoor/outdoor shades/blinds around 10 a.m. to trap the cooler air inside and block the sun
  • Open windows and doors around 10 p.m. to let the cooler overnight air in (check the outdoor temperature is indeed lower than indoors)
  • Use multiple fans strategically to help move cooler air into the home overnight
  • Consider getting an air conditioner for your home; if you have air conditioning be sure to turn it on
  • Monitor indoor temperatures for yourself and those you are checking on
  • Watch for symptoms of heat exhaustion and heat stroke
  • Wildfire smoke can also cause health problems. During both wildfire smoke and heat events consider also filtering your air using HEPA air cleaners. Find out more about wildfire smoke.

Check in on your neighbours, friends and family

During previous heat events, a large proportion of the people who died were at home and socially isolated. Check in on your neighbours, friends and family often to ensure they are able to stay cool, and  have a plan in place. This can save lives.

Heat warnings and extreme heat emergencies

Environment and Climate Change Canada issues both Heat Warnings (Level 1) and Extreme Heat Emergencies (Level 2) across the province of BC.  

Different temperature thresholds are set for Heat Warnings for different parts of the province, as the relationship between heat and mortality differs. Learn more information on heat alert criteria with map included


Know where to get information on heat alerts



SOURCE: Extreme heat ( )
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