Environment Canada has issued an extreme cold warning as Guelph and Waterloo Region are in for a frigid night on Tuesday.
The agency said it expects a temperature as low as -27 C with wind chill values between -28 and -33.
Residents are being urged to stay inside and keep their pets inside as well. Anyone who needs to go out should dress warmly with layers and the outer layer should be wind resistant.
Frostbite can develop within minutes on exposed skin, Environment Canada said.
Extreme cold warnings are in effect for most of Ontario and even stretch into Quebec. The Sudbury area is expecting wind chill values of around -40.
Old Man Winter won’t give Guelph and Waterloo Region much of a reprieve on Wednesday with a high of -13 C and a low of -17 C forecasted by Environment Canada.
The two jurisdictions have opened a number of warming centres.