HEALTH: Can you take the heat?



CANADA has been in for scorching temperatures throughout summer and the heat alerts / warnings seem to continue. So far, there have been over 100 heat warnings across Canada that have been impacting people’s health and lives with deaths also occurring in certain parts of Canada. It is important for Canadians to be more aware of the impact extreme heat can have on health, identify signs, know how to take adequate steps, and plan your summer plans accordingly.

Additionally, it is imperative to know who are more vulnerable and taking extra precautions to prevent and manage issues (for e.g. do not leave your child unattended in a car, and also not your pets)

‘Extreme heat event’ is thought to most accurately describe a prolonged episode of hot environmental conditions. Heat warnings in Canada are issued when the temperature is at or higher than a certain temperature for two or more consecutive days. For B.C., that temperature depends on the location, with the number being 29°C for the Northeast, 28°C for the Northwest, 35°C for the Southeast and 29°C in Southwest B.C.


Why does it matter?

Extreme heat events have led to a significant number of preventable deaths. The 2003 European heat wave caused 70,000 deaths and in 2010 a Russian heat wave caused 55,000 deaths. During the current heatwave in Quebec over 80 deaths are being blamed on the heat. With climate change, the frequency, duration and intensity of extreme heat events are expected to increase.


Who is more vulnerable?

Seniors, children, those with chronic and mental health conditions, on medications, bed-ridden/difficulty in self-care, low socio-economic situation, poor social support, those who are physically active, and newcomers to Canada.

The impact on health involves heat illness which involves the body’s inability to cope with heat. The stages of heat illness range from heat edema (swelling), heat rash, heat cramps, going to more severe issues such as heat syncope (fainting), heat exhaustion and heat stroke.


How to manage heat illness?

Health Canada, Environment Canada and Public Health provide a number of suggestions to help one protect themselves from the heat. First, it is always good to know your risks, see resources (from Environment Canada and public health) or talk to your family doctor to see if you fall under a higher risk category. Then it important to keep up with the news, weather reports and forecasts to know if there are concerns (it would be helpful to check this prior to planning out an outdoor activity, trip or event). Ensure your a/c is working adequately or get to know where ‘Cooling Centres’ are in your area. Cooling centres are designated public places set up by your regional public health which help you cool off during a heat warning.

Another way you could help is reaching out to your vulnerable family members, friends and neighbours to check on how they are handling the heat.

Someone experiencing heat illness usually experiences symptoms such as dizziness, feeling faint, headache, nausea, increased thirst or feeling their breathing or heart rate is fast. When experiencing this, go to a cool environment, drink fluids, and depending on the severity or risk, seek medical attention. 

Further information and resources are available through Health Canada, Environment Canada and your regional public health authority.

Extreme Heat (Health Canada)

Climate Change and Health (Health Canada)


Dr. Farhan M. Asrar is Assistant Professor with the Department of Family and Community Medicine (DFCM) at University of Toronto and Cross-Appointed with the Dalla Lana School of Public Health. He is also the Physician Research Lead for the Credit Valley and Summerville Family Medicine Teaching Units (Trillium Health Partners). He trained in family medicine and public health & preventive medicine. He is also a CFPC AQHI Trainer under the CFPC Train-the-Trainer Project which is an educational outreach program (organized by the College of Family Physicians of Canada and funded by Health Canada) This program educates health professionals on Safe Environments, including climate change and health, the Air Quality Health Index (AQHI) and Radon. Dr. Asrar has also been the recipient of several local and national awards.



Extreme Heat Event Guidelines: Technical Guide for Healthcare workers (Health Canada)

©All Rights Reserved. Extreme Heat Events Guidelines: Technical Guide for Health Care Workers. Health Canada, 2011. Adapted and reproduced with permission from the Minister of Health, 2017.


Extreme Heat Event Guidelines: User Guide for Health care workers and Health administrators (Health Canada)

©All Rights Reserved. Extreme Heat Events Guidelines: User Guide for Health Care Worker and Health Administrators. Health Canada, 2011. Adapted and reproduced with permission from the Minister of Health, 2017.