Cold weather can be harmful to your patient’s health. Exposure to cold weather and/or wintry conditions can increase the immediate risk of cold-related injuries including hypothermia and frostbite. Cold weather, even with moderate temperature changes, can also increase the risk of cardiovascular-related mortality for up to several days after exposure.

The risk of cold-related injuries and illnesses depends on several factors, such as the current weather conditions (temperature, wind, and precipitation), protective clothing and duration of exposure.

Groups At Increased Risk for Cold-Related Health Effects Include:

While anyone who isn’t dressed warmly is at risk in cold weather, some individuals are at increased risk:

  • People with pre-existing heart conditions or chronic respiratory illness
  • Older adults
  • Infants and young children
  • People who work or do physical activity outside for extended periods
  • People who are experiencing homelessness
  • People who are living in a home without adequate electricity or heat

Extreme Cold Weather

Environment and Climate Change Canada issues Extreme Cold Alerts across Canada. An Extreme Cold Alert is issued for southern Ontario (including Toronto) when the temperature or wind chill is forecasted to reach minus 30 for at least two hours.

The definition of extreme cold weather is different in many areas of the country due to local climate. In general, for people who are outside for long periods of time without adequate protective clothing, the risk of hypothermia or frostbite is present at a wind chill of -10 and below, and at wind chills of -28 and below, frostbite can occur within minutes to exposed skin.

The Canadian Pediatric Society advises parents to reduce the amount of time children spend outdoors at a temperature of -15C or colder and to consider keeping children indoors when the windchill is -27 or colder.

A review of the diagnosis and management of hypothermia and cold weather injuries was published in 2019 in the American Family Physician journal.

Warming Centres

The City of Toronto activates Warming Centres during the winter months to ensure warm spaces are available for those experiencing homelessness. Find more information on the activation process and current status of Warming Centres and services for people who are experiencing homelessness.

If there is a need to support a person at risk, call 311 for information about City services and programs, including cold weather response.

Cold Weather Tips for Vulnerable Patients & Caregivers

More information for Health Care Providers