Ottawa social workers are checking in with seniors and others who may need help as temperatures dropped below -20 C Wednesday night.
Environment Canada said the temperature was expected to fall to -22 C, with windchill making the temperature feel more like -28 C.
At 1 a.m. Thursday, the temperature hit -25 C.
The colder conditions have prompted volunteers at the Good Companions Seniors' Centre to phone seniors this week to ensure they have the food and assistance they need.
Judy Bedell, the head of community support for the centre, said they are reaching out to the seniors who have no family or support network and who may need to go outside for food or medication.
"Older adults don't have the meat on their bones as some of us young people do. But another concern is that people can become frailer every day," said Bedell.
Irene Pengelly, one of 200 seniors who got the call from the centre this week, said extreme cold can be difficult on her routine.
"It's frustrating when I can't do my walk, but I walk up and down the hallway," said Pengelly, who walks gingerly with a brace.
Staff at the Ottawa Mission homeless shelter are also doing the same, handing out hats and mittens to the men outside and encouraging them to come in and get warm.
The temperatures are expected to rise heading into the weekend, with overnight lows expected to be -7 C on Friday and Saturday, and -8 C on Sunday.