Environment Canada and several GTA-area municipalities have issued cold weather alerts for much of the coming weekend, with meteorologists projecting temperatures could fall to -23 C without windchill tonight.

Environment Canada issued an extreme cold warning for Toronto, the GTA and most of southern Ontario Friday morning, saying a cold front will bring extreme cold and “gusty northwest winds,” to the area by Friday night.

They say the wind chill could make Friday evening feel as cold as -35 C.

The daytime temperature on Saturday in Toronto is expected to reach -15 C with clear skies, and on Sunday a low of -12 C is expected.

Medical officers in both Toronto and York Region issued their own alerts for residents. They say there is an elevated risk for those with exposed skin to develop frostbite and those with heart problems should stay indoors.

The City of Toronto has opened cold weather alert drop in centres and charitable organizations that serve the homeless have been urged to relax normal restrictions on service.

York Region’s Public Health unit has issued a cold weather warning in effect until Sunday.

Two emergency overnight shelters are open in the region to accommodate anyone who fears they would otherwise have to spend the night outside.