Forecasters are warning about dangerous, arctic cold moving into the Chicago area that is expected to bring wind chills as low as -40 degrees in the coming days.
The National Weather Service (NWS) issued an extreme cold watch on Wednesday morning for the northern Illinois area.
The watch covers the Winnebago, Boone, McHenry, Lake, Cook, DeKalb, Kane, DuPage, Will, Ogle, Lee, LaSalle, Kendall, Grundy, Kankakee, Livingston, Iroquois and Ford counties.
The watch said dangerous cold wind chills will spread across the northeast Illinois area from Thursday evening through Friday morning.
The dangerously cold wind chills could cause frostbite on exposed skin in as little as 10 minutes.
The NWS said wind chills could reach 35 degrees below zero but some models show wind chills potentially reaching lower than 40 degrees below zero along the Illinois-Wisconsin border.
Some areas will likely see actual temperatures remaining below zero all day on Friday.
While the watch is currently only in effect through Friday morning, the dangerous cold is expected to continue into Friday evening and Saturday morning.
The NWS said Saturday afternoon and Sunday morning will still be very cold, with low temperatures of negative five degrees to two degrees and negative five to negative 15 degree wind chills.
The watch said people should dress in several layers, including a hat, face mask and gloves if going outside.
Residents are urged to check on their neighbors, family and friends and keep pets indoors as much as possible.
Residents are also urged to stay indoors as much as possible and let faucets drip slowly.
The NWS also warned of gusty scattered snow showers expected to move across the area on Wednesday evening that may result in snow accumulations up to an inch and hazardous travel.
Strong westerly winds may gust over 40 mph, which may cause blowing snow and low visibility in open areas.