
In Focus
Polar vortex plunges vast swath of U.S. into deep freeze
A harsh winter blast from the north is bringing dangerous low temperatures to much of the eastern two-thirds of the country.

Chicago
A man walks along an ice-covered breakwall along Lake Michigan while temperatures were hovering around -20 degrees and wind chills nearing -50 degrees on Jan. 31.
Businesses and schools have closed, Amtrak has suspended service into the city, more than a thousand flights have been cancelled and mail delivery has been suspended as the city copes with record-setting low temperatures.

Buffalo, New York
A woman clears a car in the snow.
The National Weather Service described the polar vortex system surging from the north as "one of the coldest arctic air mass intrusions in recent memory."









Janesville, Wisconsin
Nathan Tearman, front, gets help from his brother James as they shovel their driveway on Jan. 28 after a winter snowstorm.
Gov. Tony Evers declared a state of emergency shortly after noon Monday, citing the snow and severe cold that were forecast for the days ahead.
