Environmental Health

Heat Warnings and Extended Heat Warnings

Toronto Public Health issues warnings for high heat or humidity that is expected to last two or more days.  During this time, heat warning information (located above) will be updated daily to reflect the current status.  Toronto Public Health follows a provincial Harmonized Heat Warning and Information System for dealing with heat events in the City of Toronto.

Toronto Public Health staff will monitor this system to determine when the Medical Officer of Health should declare a heat warning or extended heat warning.  This coordinated provincial system provides a consistent approach for processing and issuing heat warnings in Ontario.  It also provides evidence-based heat warning triggers which are based on the association between temperature, humidex and mortality.

During Hot Weather Conditions

Please call or visit family, friends and neighbours, especially isolated seniors to make sure they are alright.

Other groups at risk include:

  • people with chronic and pre-existing illnesses
  • infants and young children
  • people on certain medications
  • those who are marginally housed or homeless

Beat the Heat

Picture of a boy riding in a car with the window down

Heat and Car Safety

Find out how rising temperatures inside a car can be dangerous for children. 

Information for Landlords and Community Partners

Extreme Heat in Apartment Buildings