The Canadian Environment Ministry has issued a heat warning covering four provinces as a two-day heat event is expected across most of the central and eastern parts of the country.

The Meteorological Agency's warning applies to vast areas of southern Ontario, southern Quebec, New Brunswick, and Nova Scotia.

The Canadian Environment Ministry says maximum temperatures are expected to reach or exceed 30 degrees Celsius and reach the low forties when combined with humidity.

It says overnight temperatures are expected to be between the low to mid-twenties, slightly relieving the daytime heat.

The Air Quality Health Index shows that southern Ontario is currently in the low to moderate risk category, with southern Quebec, New Brunswick, and Nova Scotia classified in the low risk category.

Temperatures are expected to be cooler on Monday, although parts of Nova Scotia may continue to feel very hot throughout the day.

Residents are advised to monitor signs of heat illness such as swelling, cramps, and fainting, drink plenty of water, stay in a cool place, and check on elderly family, friends, and neighbors.