**This warning was last updated at 1:39**
Environment Canada has issued an extreme cold warning for Waterloo Region and much of southern Ontario calling for frigid temperatures.
Wind chills values are expected to plummet to near minus 30 by early Sunday morning. Wind chills will remain around minus 30 throughout the day as winds gust from the northwest up to 70 km/h.
Wind chills will fall to minus 35 Sunday night.
The weather agency says we can expect wind chill values near minus 30 Monday night as well.
A milder airmass is expected to move in by Tuesday, which will improve temperatures.
Extreme cold warnings are issued when temperatures or wind chill values create a risk to health, such as frost bite and hypothermia.
People at the greatest risk are young children, older adults, people with chronic illnesses, people working or exercising outdoors, and those without proper shelter.