Environment

Extreme Temperature

Key Messages
Heat-related ER Visits
Cold-related ER Visits
Technical Notes

Key Messages

The frequency and intensity of extreme temperature events is expected to increase as a result of climate change, and this poses risks to human health.
The number of heat-related emergency room visits tends to be higher during years when daily temperatures reach or exceed the 30°C mark on 10 or more days.
Heat-related emergency room visits were more common in youth, younger adults and the elderly, and among men.
The rate of cold-related emergency room visits was less closely tied to the number of days with minimum temperatures below -30°C.
Cold-related emergency room visits were higher in youth and among males

Heat-related emergency room visits

The age-standardized rate of emergency room visits related to extreme heat across 2003 to 2021 varied from 7 (4.8, 9.9) visits per 100,000 population in 2004 to 24 (20.4, 28.8) visits per 100,000 population in 2018 across the summer months.
The rate of heat-related emergency room visits was higher in years with more days above 30°C.
2016 had the highest number of days with temperatures above 30°C, and one of the highest rates of heat-related emergency room visits.
The rate of heat-related emergency room visits was higher in youth (aged 10-19 years), adults (20-44 years), and older adults (75+ years).
Males had a significantly higher rate of heat-related emergency room visits with an average of 19 (17.9, 20.3) visits per 100,000 population per year across 2003-2021, compared to 11 (10.3, 12.1) visits per 100,000 population among females.

191126HeatEDVis2003to2018

191126HeatEDVisits_ASR_2003tp2018

191126HeatEDVisits_Sex_2003to2018

Cold-related emergency room visits

The age-standardized rate of emergency room visits related to extreme cold across the 2003/2004 to 2021/2022 winters varied from 7 (4.3, 9.6) visits per 100,000 population in 2011/2012 to 25 (21.3, 30.0) visits per 100,000 population in the 2014/2015 winter.
The rate of cold-related emergency room visits was less closely tied to the number of days with minimum temperatures below -30°C.
There were two days with minimum temperatures below -30°C in Barrie-Oro region in the winter of 2021/2022, the first time since the winter of 2017/2018.
Youth, aged 10-19 years, had significantly higher rates of emergency room visits related to cold exposures, with 20 (17.1, 22.1) visits per 100,000 population, compared to 15 or fewer visits per 100,000 population in all other age groups.
Males also had significantly higher rates of emergency room visits related to extreme cold, with an average of 20 (18.6, 20.1) visits per 100,000 males compared to 7 (6.7, 8.3) visits per 100,000 females per year across the 2003/2004 to 2021/2022 winters.

191126ColdEDVis2003to2018

191126ColdEDVisits_ASR_2003to2018

191126ColdEDVisits_Sex_2003to2018

Technical Notes

Heat-related emergency room visits include ICD-10 codes for exposure to excessive natural heat (X30) and effects of heat and light (T67) which include heat stroke and heat exhaustion.

Cold-related emergency room visits include ICD-10 codes for frostbite (T33-T35), hypothermia (T68) and exposure to excessive natural cold (X31) including chillblains.

Thresholds for extreme heat and extreme cold are identified based on Environment Canada’s extreme temperature notification thresholds for heat and cold.

Please note that the COVID-19 pandemic had a considerable impact on emergency department visits in 2020, and may impact exposure to extreme temperatures and emergency care seeking behaviours in other as yet unclear ways.