Chicago area, Dangerous and frigid temperatures

A polar vortex dipping down from Siberia will bring a cold front with frigid temperatures to nearly 300 million Americans.
According to the National Weather Service, a polar vortex will impact most of the country this weekend, here is what you need ...
The coldest weather of the season to date will be due to a phenomenon called a polar vortex, an upper-level ... Lang in New York and Brendan O'Brien in Chicago; Editing by Frank McGurty and ...