Toronto's medical officer of health issued a heat alert for the city for Victoria Day.

The alert is in effect until further notice.

The Environment Canada forecast for the holiday Monday was a high of 27 C in Toronto, with a UV index of eight or very high.

People are encouraged to check on family, friends and neighbours, especially isolated adults and seniors who are at greater risk of suffering from heat-related illness to make sure they are OK.

Other groups at risk include people with chronic illnesses, young children and the homeless.

The public is advised to beat the heat by staying out of the sun, drinking a lot of water, going to air-conditioned places and not doing strenuous activities outdoors.

The medical officer of health also warned against leaving the elderly, children or pets unattended in a car.