Environment Canada has issued an extreme cold warning for Grey-Bruce and northern Huron-Perth counties.
With the wind chill, temperatures are expected to be near minus 30 on Saturday night.
The agency warned of cold-related symptoms like shortness of breath, chest pain, muscle pain and weakness, numbness, and colour change in fingers and toes.
"Extreme cold puts everyone at risk," the weather agency said in a statement. "If it's too cold for you to stay outside, it's too cold for your pet to stay outside."
Temperatures are expected to warm up on Sunday morning.
