SIOUX FALLS, S.D. — It’s been a day of surviving the bitter cold.

The windchill factor dipped to dangerous levels last night and continued into this morning.

Unfortunately some people got home from work last night only to find out their furnaces had quit working.

“As soon as I came home yesterday I thought it felt a little bit cool in the house,” Donna Fuoss said.

Donna Fuoss says the moment she walked into the house, she suspected something was wrong with the furnace, so she called her husband.

“I said ‘I don’t think you really want to hear this, but the furnace isn’t really working, oh crap,'” Fuoss said.

So she began calling around to find someone to fix it.

“They said it could take 24 hours for a serviceman and I thought wow,” Fuoss said.

Thanks to three space heaters and a nice warm gas fireplace, they kept the house fairly warm.

They’re not the only ones dealing with furnace failures.

At Howe Inc, business is really heating up today and not just in its fabrication room.

It’s dispatch center for service repair has been fielding calls all day.

“The phones always start in the morning, slammed in the morning, dies off a tiny bit lunchtime gets busy and dies off a bit again, then everybody starts getting home from work we start getting busy again,” Adam Sunderman said.

The service technicians at Howe make all kinds of repairs to your furnace and a lot of them start with the air filter.

One quick tip is to make sure your air filter is new.

“When the filter is clogged the furnace isn’t able to move the air that it needs to, things get too hot, the furnace knows that, so it trips a limit switch before it gets to a dangerous level,” Sunderman said.

On days like today, Sunderman says they’ll respond anywhere from 70-80 calls and they’re not all heat related.

“We get no heat calls, we get frozen sprinkler lines, we get all kinds of things in the plumbing world caused by the extreme temperatures,” Sunderman said.

Temperatures Fuoss hopes they don’t have to deal with for much longer.

“Our electric heaters and three dogs that keep us nice and toasty at night,” Fuoss said.