A deep freeze held Toronto in its grip on Monday as temperatures stayed well below the freezing point and city officials kept an extreme cold weather alert in place for the third straight day.

Temperatures were expected to hit a high of -11C, but a wind chill factor was expected to make it feel more like -28C. Officials warned that under these conditions skin can freeze in less than 10 minutes.

The cold weather alert triggers Toronto to open an additional 80 emergency sleeping spaces for the homeless and provide extra street outreach services.

Emergency TTC tickets will also be issued through drop-in centres, allowing homeless people to get a free ride to shelters.

The public can also call a 24-hour toll-free number if they see a homeless person sleeping outside in the cold weather. The Street Helpline can be reached at 1-866-392-3777.

Frigid temperatures also triggered two school closures. Orangeville Christian School and Holland Marsh Christian School closed their doors for the day. School bus service for the Dufferin-Peel Catholic District School Board in the County of Dufferin was also cancelled.

But the majority of schools remained open and students were going to classes, bundled-up against the biting cold.

Crossing Guard Mona Piper has 35 years experience helping students get to school. During those years she has learned how to prepare for a cold day on the job.

"Pants and ski pants, warm socks, heavy boots to keep my toes warm ... and about three pairs of gloves," Piper said.

People caught outside waiting for a bus said it was an uncomfortable day to be outside.

"You have to be bundled up to the max," one man told CTV's Austin Delaney.

Toronto was not alone in the deep freeze. Environment Canada also issued wind chill warnings for much of Ontario, saying it could feel as cold as -40C in some regions, particularly the eastern region of the province.

A wind chill warning was also issued for much of southern Ontario. Temperatures in cities like Windsor dipped down to -20C without wind chill.

"But you factor in the strong winds and we saw wind chills that, right across the province, were typically minus 30 in the south and well into minus 40s in the north," Dave Phillips of Environment Canada told CTV Newsnet.

Several snowsquall warnings were issued due to 15 to 30 centimetres of wind-whipped lake-effect snow blowing in off Lake Huron and Georgian Bay.

Provincial police said several roads have been closed due to poor visibility and blizzard conditions in Bruce, Grey and northern Perth, Huron and Wellington counties.

Many vehicles wound up in ditches as a result, police said.

The bone-chilling temperatures are expected to continue for the next several days.

With a report from CTV's Austin Delaney and files from The Canadian Press