Cold wave has much the nation shivering.
A huge blast of arctic air has much of the nation in its grip.
Brutal cold in Chicago challenged firefighters dousing a big warehouse fire overnight.
The building was converted from fire into ice that stayed frozen well into Wednesday, day four of dangerously cold weather that's gripped much of the Midwest and Northeast.
Temperatures in Wilkes Barre, Pennsylvania climbed to double digits, but not before a single-digit start to the school day.
Wind chills made feel it like -5 degrees.
The deep freeze dipped into the Deep South, too.
The spray below Fontana Dam, North Carolina froze instantly.
Lake effect snow is piling up in western New York.
Forecasters say the air just north of Detroit and the Great Lakes is colder than that at the North Pole.
The bitter conditions are expected to linger into the weekend in the Midwest and through the eastern half of the U.S.