Toronto's Medical Officer of Health has upgraded the heat alert for Toronto to an extreme heat alert on Monday morning.

The extreme heat alert will be in effect until further notice, and cooling centres are now open at the following locations:

• Metro Hall - 55 John St. (24 hours)

• East York Civic Centre - 850 Coxwell Ave. (11 a.m. to 7 p.m.)

• North York Civic Centre - 5100 Yonge St. (11 a.m. to 7 p.m.)

• Driftwood Community Centre - 4401 Jane St. (11 a.m. to 7 p.m.)

• Etobicoke Olympium - 590 Rathburn Rd. (11 a.m. to 7 p.m.)

• McGregor Community Centre - 2231 Lawrence Ave. E. (11 a.m. to 7 p.m.) • Centennial Park Community Centre - 1967 Ellesmere Rd. (11 a.m. to 7 p.m.)

There's also a smog advisory in effect. Environment Canada predicts the air quality for the GTA will be in the poor range on Monday. Hot weather, combined with a southwesterly flow of polluted air from the U.S. is to blame for elevated smog levels.

A heat alert was issued on Sunday by the city amid soaring temperatures. Temperatures are expected to be over 30 C this week.

The city is encouraging people to call or visit 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 okay. Other groups at risk include people with chronic and pre-existing illnesses, infants and young children, people on certain medications and those who are marginally housed or homeless.

When an alert is declared, those who need assistance or have heat-related inquiries may call the Canadian Red Cross Heat Information Line at 416-480-2615.