Extreme Heat Background

Woman in her 80s fans herself in a summer heat wave. She is suffering from the causes of energy poverty. She has no money for air conditioning.

The Danger of Extreme Heat

Extreme heat is a serious and escalating public health emergency. Extreme heat is especially dangerous for elderly people, people with disabilities, people with certain pre-existing medical conditions or taking some medication, children, low-income tenants, and more isolated individuals.

The human body also requires cooling at night, and buildings that retain the heat of a hot day can be very hazardous or even fatal to human health.[1]

Modeling from the City of Toronto forecasts that the number of days where the temperature exceeds 30 degrees Celsius will triple by 2040-2050, increasing from 20 days to 66 days every year.[2]

In Ontario, between 1996 and 2010, each five degrees Celsius increase in temperature during the summer was associated with a 2.5 percent increase in death, with a particular link to respiratory deaths.[3]

During the 2021 extreme heat event in British Columbia, the majority of deaths occurred inside people’s homes. According to Dr. Sarah Henderson of the BC Centre of Disease Control, “People don’t die because it is hot outside; they die because it is hot inside.”[4] 98% of the deaths that occurred during the BC extreme heat event occurred indoors.[5]

Recent City Actions

Toronto City Council requested a staff report on an adequate temperature by-law that was due in the first quarter of this year. [6] However, that report has not yet been released.

The Toronto Board of Health has also instructed the Medical Officer of Health to begin monitoring climate change health impacts in the City. However, the first report on the climate change health surveillance framework is not due back to the Board of Health until the beginning of 2025.[7]

The City of Toronto currently has a by-law preventing tenants of multi-residential buildings from opening their windows more than 10 centimeters wide,[8] which limits tenants’ ability to cool their homes at night.