Woman Jogging
A woman jogs along the Charles River in Cambridge, Mass. Reuters

The polar vortex brought disruption to air traffic and morning commutes, warnings of wind chills and frostbite, and brutally cold temperatures across a large portion of the United States.

In parts of the Midwest, temperatures reached as low as 40 degrees below zero and Chicago’s O’Hare International Airport canceled half of its flights because fuel supplies froze, Reuters reported.

At least four deaths were blamed on the frigid weather, including a 48-year-old man from Chicago who died of a heart attack shortly after shoveling snow and an elderly Indianapolis woman who was found outside her home.

Just what do these cold temperatures look like? Here are a few photos showing the effects of the polar vortex:

Woman Falling NYC
A woman falls on ice in Manhattan. Reuters
Charles River
Birds gather by the partially frozen river in Boston. Reuters
Gust Of Snow Chicago
A woman walks through a gust of blowing snow in Chicago Reuters
Detroit Truck
Barry Tilton cleans the snow off of his pick-up truck in the midtown neighborhood of Detroit, Michigan January 6, 2014. Reuters
Indianapolis Snow Plow
Snow plows rumble through the streets of Indianapolis. Reuters
Indianapolis dogs
A couple walk their dogs on a snow-covered Indianapolis street. Reuters
Indianapolis
A man clears snow from his car in Indianapolis. Reuters
Chicago Bus Shelter.
A person walking in a Chicago bus shelter during the polar vortex. Reuters
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