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.

A man is bundled up against the cold on New York's 34th Street in Midtown Manhattan Wednesday, Jan. 23, 2013. The temperature was around 12 degrees, but with wind gusts of 15-20 mph, it felt more like five below as people started their day in New York City. (AP Photo/Mark Lennihan)
A man is bundled up against the cold on New York's 34th Street in Midtown Manhattan Wednesday, Jan. 23, 2013. The temperature was around 12 degrees, but with wind gusts of 15-20 mph, it felt more like five below as people started their day in New York City. (AP Photo/Mark Lennihan)
A man is bundled up against the cold on New York's 34th Street in Midtown Manhattan Wednesday, Jan. 23, 2013. The temperature was around 12 degrees, but with wind gusts of 15-20 mph, it felt more like five below as people started their day in New York City. (AP Photo/Mark Lennihan)
University of Wisconsin-Madison student Marisa Weich contends with sub-zero wind chill temperatures while making her way to class on the campus Tuesday, Jan. 22, 2013. (AP Photo/Wisconsin State Journal, John Hart)
University of Wisconsin-Madison student Marisa Weich contends with sub-zero wind chill temperatures while making her way to class on the campus Tuesday, Jan. 22, 2013. (AP Photo/Wisconsin State Journal, John Hart)
University of Wisconsin-Madison student Marisa Weich contends with sub-zero wind chill temperatures while making her way to class on the campus Tuesday, Jan. 22, 2013. (AP Photo/Wisconsin State Journal, John Hart)
Ice crystals form frost on the window of a home in Medina, Minn., as the area experiences subzero temperatures on Monday, Jan. 21, 2013. (AP Photo/The Star Tribune, Richard Sennott)
Ice crystals form frost on the window of a home in Medina, Minn., as the area experiences subzero temperatures on Monday, Jan. 21, 2013. (AP Photo/The Star Tribune, Richard Sennott)
Ice crystals form frost on the window of a home in Medina, Minn., as the area experiences subzero temperatures on Monday, Jan. 21, 2013. (AP Photo/The Star Tribune, Richard Sennott)
The breath of a bicyclist turns to steam and his beard frosts over as he bikes down the Nicollet Mall Tuesday, Jan. 22, 2013 in downtown Minneapolis where temperatures were in the double-digit, sub-zero numbers. (AP Photo/Jim Mone)
The breath of a bicyclist turns to steam and his beard frosts over as he bikes down the Nicollet Mall Tuesday, Jan. 22, 2013 in downtown Minneapolis where temperatures were in the double-digit, sub-zero numbers. (AP Photo/Jim Mone)
The breath of a bicyclist turns to steam and his beard frosts over as he bikes down the Nicollet Mall Tuesday, Jan. 22, 2013 in downtown Minneapolis where temperatures were in the double-digit, sub-zero numbers. (AP Photo/Jim Mone)
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)
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)
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)
A Commuter bundles 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)
A Commuter bundles 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)
A Commuter bundles 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)

What to Read Next