Bundle up, Toronto. It's going to feel like 35 tonight and even colder Sunday

Environment Canada issued an extreme cold warning for Toronto and surrounding regions as wind chill values are expected to approach35 at times over the weekend.

An arctic air mass will grip most of southern Ontario until Tuesday morning, the federal weather agency said. It will feel close to35 overnight Saturday, and38overnight Sunday.

"Cover up, frostbite can develop within minutes on exposed skin, especially with wind chill," Environment Canada said in an alert sent shortly before 11 a.m.

"Risks are greater for young children, older adults, people with chronic illnesses, people working or exercising outdoors and those without proper shelter," it continued.

Toronto proper will see a high of12 C on Saturday afternoon, though it will feel more like23. It will only get colder heading into the evening. Sunday's high is forecast as15 C, with wind chill values of26 anticipated by the afternoon.

The massive cold weather system causing the deep freeze moved across the northern U.S.this week and is expected to bring snow to the entire Golden Horseshoe. Hamilton and Niagara willsee the most snowfall, according to Environment Canada, with between 20 and 35centimetres accumulating throughout the day. Some localized areas could see up to 45 centimetres before Sunday morning.

Areas of Toronto closest to Lake Ontario are forecast to get between five and 10 centimetres of snow, with less falling further north of the lake.

However, wind gusts of up to 60 km/h throughout the weekendcould cause periods of blowing snow, making for dangerous driving conditions in the GTA.

"Travel could be quite treacherous at times this afternoon and this evening," said Glenn Robinson, severe weather meteorologist for Environment Canada.

The bitter cold could also reduce the effectiveness of road salt, he added. Highways, roads, walkways and parking lots could become icy and slippery. Problems for drivers and pedestrians could persist through the morning rush hour on Monday.

Both local and provincial police forces warned drivers and pedestrians to be wary of difficult conditions and to keep a safe distance from snow plows on the roads.

According to OPP Sgt. Kerry Schmidt, more than 150 crashes were reported on GTA roads on Saturday. In the City of Toronto, 91 collisions were reported between noon and about 6 p.m., according to Katrina Arrogante, spokesperson for Toronto police.

Three hundred sidewalk plows, 600 road plows and 200 salt trucks are on hand in Toronto, according to Mark Mills, the city's superintendent of road operations.

"It's safe to say that of the 1,110 pieces of equipment we have available to us, at some point during this storm all that equipment will be used," Mills said.

You can follow the plowing in your area with the city's interactive map.

Homeless population at risk

The City of Toronto also issued its own extreme cold weather alert on Saturday. Part of that process includes measures to reduce the risks that those sleeping on the street face when temperatures become dangerously cold.

According to street nurse and advocate for homeless people Cathy Crowe, this winter is the first that the Out of the Cold program a system of temporary shelters provided by the interfaith community is running over-capacity on a consistent basis.

Todd Orvitz, director of strategic and policy solutions with the city, said the network of shelters and respite centres are prepared to deal with an influx of people this weekend.

"We've been able to build appropriate capacity and contingency into the system to allow us to expand the system on nights like this," he said, adding that all residents can help keep vulernable populations safe.

If you see a person in need of assistance on the street, call 311, Orvitz said. A street outreach team can be dispatched to their location. In more serious cases, call 911, he advised.

Crowe and other activists plan to call on Toronto Mayor John Tory to declare a state of emergency at a meeting of his executive committee next week. The group says such a move would allow the city to pursue additional funds from the province and federal government to address the ongoing prevalance of homelessness in the city.

Meanwhile on Saturday morning, ateam of volunteers with the Toronto-area charity Engage and Change put together some 3,000 cold weather survival kits that will be distributed to the city's homeless population throughout the weekend. The kits include a sleeping bag, warm clothing and a variety of basic necessities.