By Lauren Victory

(CBS) – A wintry weather combo of snow and extreme cold creates a critical concern for Chicago’s homeless.

Staff at Franciscan Outreach say the shelter’s been over capacity since Tuesday, but they’re hoping to help even more people this weekend as forecasts calling for wind chills in the negatives.

They check the sidewalks, park and viaduct around Harrison and California multiple times a day to make sure no one is staying out in the potentially deadly elements.

“We have seen definitely a lot of our guests who have lost many limbs due to the cold,” program director Cynthia Northington says.

Franciscan Outreach is serving as a 24/7 warming center at the request of the city, until Tuesday.