Central Wisconsin felt its coldest temperatures so far this winter.
Health officials say it's important to be mindful of winter safety.
"Hypothermia and frost bite are the two things that we worry most about," said Dale Grosskurth from the Marathon County Health Department. "Hypothermia is when the body's temperature drops too low and it's usually noticed by uncontrollable shivering. People become disoriented, their speech will slur."
If you start to see any of the warning signs of hypothermia, get inside and maybe even seek medical attention, Grosskurth said.
Numb or pale skin can be in indication of frost bite, he said.
One way to avoid these scary cold conditions is defrosting in a warming center.
"We're definitely seeing more people come in as it gets colder outside," said Kathleen Kosiec, library specialist at the Marathon County Public Library in Wausau.
Everyone is welcome to come in to the Marathon County Public Libraries and warm up during business hours.
"I come in the library to warm up and also to look up a bunch of stuff on the computer," said Doug Smith of Wausau.
While the weather might be brisk, Central Wisconsin will surely see colder days ahead.
"I think that I'm kind of immune to it after living here so long. I didn't even really notice it was that cold," Casey Huxtable of Wausau.