In response to record-low temperatures, Gov. Pat Quinn on Monday issued a state disaster declaration and activated the Illinois National Guard to provide aid.
"It's imperative that the people of Illinois work together as a family to help each other out," Quinn said during a Monday news conference. "We have to get through it. We will get through it."
Quinn said all the state's resources were activated as more than 11 inches of snow poured onto northern Illinois through Sunday and wind chills as low as -47 degrees gripped Chicago's suburbs on Monday morning.
The Illinois National Guard helped emergency crews provide assistance to residents, Quinn said, and nearly 3,700 Illinois Department of Transportation employees and 1,755 trucks were deployed statewide.
Still, state Transportation Secretary Ann Schneider urged residents to avoid travel as extreme cold conditions persist.
"We're still facing some very dangerous situations," Schneider said, noting drifting snow and black ice in some areas. "It's still very treacherous for motorists."
IDOT crews were dispatched since last Tuesday, Schneider said, and will remain there until further notice.
"We are taking this situation minute-by-minute, day-by-day," she said. "Don't travel unless it's absolutely necessary."
There were 130 crashes and 636 motorists rescued on Illinois tollways, and dozens of cars and 20 semis were stuck in snow drifts. Officials said they were fortunate it wasn't worse.
In total 9,400 tons of salt and 1,900 gallons of liquid fluoride were used on snowy Illinois roads.