What are the impacts and extent of the polar vortex affecting the United States?

The polar vortex is bringing life-threatening cold to an 11-state region stretching from the Canadian border to Oklahoma and Texas. Wind chills have plummeted to extreme levels, reaching -51°C in North Dakota and -40°C in Montana, with the National Weather Service issuing severe warnings across the affected areas. Meteorologists predict this will be the 10th coldest polar vortex event of the season, with near-record cold temperatures expected by midweek. This weather phenomenon occurs as Arctic air that normally remains near the North Pole is being pushed southward into the United States and Europe, creating dangerous winter conditions.