It's about to get even more frigid in Toronto. 

The city's extreme cold weather alert continues Wednesday as temperatures dip to -8 C, though it will feel closer -22 throughout the morning. By tonight, the mercury will have dropped to nearly -18 C, with windchill making it seem more like -27.

The subzero temperatures have forced the holiday fair in Nathan Phillips Square to close for the day, while public health officials are reminding residents to take extra precautions to keep warm and safe.

"Those most at risk of cold-related illness are people experiencing homelessness or those under-housed, those who work outdoors, people with a pre-existing heart condition or respiratory illness, elderly people, infants and young children," a statement issued Tuesday from the city said.

"People with heart problems can experience worsening of their condition up to several days after cold weather occurs."

Shelters throughout Toronto will loosen restrictions in response to an extreme cold alert, and 'outreach' teams spend the night trying to get vulnerable people into a safe place.

Public health officials also warn residents to:

  • Check the weather before heading outside.
  • Dress appropriately for the cold and try to stay dry.
  • Drink warm fluids (alcohol not included).
  • If you're walking outside, take brief respite inside warm buildings when possible.
  • Check on vulnerable family, friends and neighbours.

The extreme cold warning remains in effect until further notice from the city. It looks like temperatures will be back to a more reasonable level by midday Friday, with daily highs over 0 C predicted for the weekend and early next week.