Commuters bundle up against extreme cold conditions Tuesday, Jan. 22, 2013, in Chicago. Temperatures in the area were hovering around zero with sub-zero wind chill reading hitting 10 below. Forecasters say waves of frigid Arctic air began moving over the region Saturday night Jan. 19, 2013. Temperatures are expected to rebound Wednesday Jan. 23, 2013. (AP Photo/M. Spencer Green)
Deep freeze grips U.S.
A cold snap has sent as waves of Arctic air swept
south from Canada, pushing temperatures to dangerous lows and leaving parts of the Midwest and Northeast reeling.