Heat advisories and warnings
Southwest Public Health will declare a heat warning when prolonged exposure to outdoor conditions could prove dangerous to public health. Environment and Climate Change Canada’s meteorological services notifies Public Health when there is an impending heat event forecast for our area.
Public Health will then issue a Heat Warning or Extended Heat Warning based on the duration and intensity of the expected conditions:
- Heat Warning – when forecast temperatures are expected to be at least 31°C and overnight temperatures are at or above 20°C for two days or the Humidex is forecasted to be at least 40°C for two days.
- Extended Heat Warning – When forecast temperatures are expected to be at least 31°C and overnight temperatures are above 20°C for three or more days or Humidex is at least 40°C for three or more days.
A heat warning or extended heat warning will be posted on Southwest Public Health’s website and social media, and will be issued to local media, child care providers and other community partners.
During an extended heat event, cooling centres like libraries, arenas and other public buildings may be opened to the public for relief from the heat. The cooling centres typically include air conditioning, seating and water and are managed by each city, town or township.
Stay safe in the heat
Public Health reminds people that the combination of high heat and high humidity can be dangerous. Anyone who experiences physical distress because of extreme temperatures should seek medical attention immediately, either by calling 911 or by going to the nearest emergency department.
Heat alert guidelines and recommendations
- Heat alert guidelines: child care centres
- Heat alert guidelines: general public
- Heat related illnesses
- UV index
- Public weather warnings
- Health Canada: Keep children cool! Protect your child from extreme heat
- Health Canada: You’re active in the heat. You’re at risk! Protect yourself from extreme heat
- Health Canada: It’s way too hot! Protect yourself from extreme heat
- Ontario Ministry of Labour: Heat Stress