(CNN) -- The National Weather Service in Chicago is asking residents not to travel unless "absolutely necessary" because a winter storm pushing through the upper Midwest has created a "potentially life threatening situation."
"Reports from media and local law enforcement officials indicate that hundreds if not thousands of vehicles have gone off the roads," the weather service said early Wednesday morning.
Illinois State Police carried out a rescue operation in Kankakee County after 20 cars were stranded in the snowstorm, where snow drifts were measured around 3 feet, the agency said.
The rescued motorists were taken to temporary warming centers in Manteno or Peotone, said state police Sgt. Angie Kinstner.
CNN's Ric Ward also contributed to this report