Ontario is preparing for a significant heat event.

According to a heat warning issued by Environment Canada for southern Ontario, including Toronto, the Humidex temperatures are expected to reach the low 40s this week. The temperatures will range from the high 20s to low 30s, but when factoring in the humidity, they could exceed 40 degrees Celsius.

The heat wave is anticipated to start on Tuesday afternoon and could persist for two to three days. The warning states that these hot and humid conditions will gradually diminish from west to east starting Wednesday night.

Similar warnings have been issued throughout the Greater Toronto Area and southern Ontario, extending from the western region near Windsor and the United States border all the way into Quebec.

Heat warnings are not limited to southern Ontario, as they extend as far north as Bracebridge, Ont., although there may be some relief in cottage country. Moreover, extensive areas of northern Ontario, including Sault Ste. Marie and Fort Frances, are expected to experience extreme heat conditions.

In light of these circumstances, the weather agency has issued a reminder for individuals to prioritize their hydration and seek shelter in cool places to stay safe.