The extremely cold January made for one of the busiest months on record for local furnace repair companies.

Some heating and cooling repair companies have had their employees working up to 16-hour days.

"Our guys are working 12, 14, 16 hours a day, six days a week," said Andrea Read of Bryant Heating and Cooling. "We have on call 24/7. That poor fella has not had a very good winter. It's been very, very busy."

Read said Bryant hasn't been this busy in 15 years.

It's a similar story at Riverside Heating and Cooling.

"Everyone's pretty desperate to stay warm," repairman Scott Hackney said.

Thursday, he was giving a furnace at tune-up at Preston Shea's home.

"The house is about 10 years old and we've had some dramatic changes in weather. We just wanted to make sure it was working properly," Shea said.

Hackney said Windsor homes aren't exactly built for the extreme cold and heavy snow.

"Old wartime houses aren't insulated as well. That's where a lot of furnaces can't keep up because they're undersized for the house," Hackney said. "We're used to plus two and minus two, so having it minus 22 degrees at night, furnaces are running constantly."

Reliance Heating and Cooling told CBC News they were too busy to conduct an interview but said there is such a demand for repair in Windsor the company has sent workers from Toronto to Windsor to help.

Environment Canada says Windsor is in for a warm weekend. Friday is to be mainly cloudy with a high of - 1 C and 30 per cent chance of flurries.

But the agency is calling for - 10 C by the end of next week.