The alert is intended to warn the public about the harmful health effects of exposure to extreme cold. It also makes available more services for those vulnerable to extreme weather, including the homeless.
There have been calls for the city to re-examine its cold weather alert system after a man found unconscious on a bus shelter bench in freezing weather died Wednesday.
Dr. David McKeown, the city's medical officer of health, was interviewed Wednesday about the cold weather alert system on CBC radio's Metro Morning. McKeown is responsible for issuing the alerts.
According to the city's Cold Weather Plan, alerts are issued when the forecast calls for temperatures colder than -15 C. But McKeown said this threshold is only a guideline and said he can issue an alert based on other factors, such as a sudden change in weather, severe wind chill or a heavy snowfall.
"People who are without shelter are at risk of premature death all winter," said McKeown. He added that the role of the cold weather alert system is "to warn people about exceptionally cold and dangerous weather."