Its a busy time for groups that help Toronto's homeless.  With wind chill set to bring temperatures in the GTA as low as -21 over the next few days, shelters are expected to fill up quickly.

That means a warm sleeping bag and winter clothing like gloves and toques can literally mean the difference between life and death for people who live on the streets.

Even for those that do get into a shelter, there is often a long, cold wait at the door.

Jody Steinhauer heads up Project Winter Survival, a group that brings volunteers and business leaders together to help homeless people through the cold months.

They collect donations of winter gear, hygiene products, and healthy food to assemble kits that are distributed by organisations like the Salvation Army and the Red Cross.

Project Winter Survival has collected $500,000 in donated gear this season, enough to keep 3,000 people warm.

However, it falls well short of the demand.

Steinhauer got requests for more than 11,000 survival kits this season alone and says demand is growing.

"There are 12 more agencies that have popped up and are now putting in outreach programs to help in their communities," she says.

The Good Neighbours Club in Moss Park also expects the cold weather to bring more people to its door.

The day-time drop-in shelter provides a safe haven and community services for men over 50 who fallen on hard times.

Shelter director Lauro Monteiro says it is occasionally challenging to convince some clients to seek a warm place to sleep after the Good Neighbours Club closes for the night, even when temperatures plummet.

Monteiro says some clients fear for their safety in the shelter system and would rather chance spending the night outside.

"We work with groups like (Project Winter Survival) to keep people as safe as we possibly can," he says.