If you're going to exercise outside in cold weather, it's important to wear the proper clothes. Practice gearing up by printing out this paper doll below and adding layers depending on the temperature and conditions where you live. Paper doll illustration by Malaka Gharib/NPR; Photograph by Becky Harlan/NPR hide caption
Pedestrians make their way down a partially plowed Murray Avenue Monday, Jan. 17, 2022, in Squirrel Hill neighborhood of Pittsburgh. Pam Panchak/AP hide caption
A worker shovels snow from a sidewalk in the Humboldt Park neighborhood of Chicago. Forecasters expect temperatures to drop around 10 degrees by Wednesday. Scott Olson/Getty Images hide caption
Frank Lettiere's eyebrows and eyelashes froze after his walk along Lake Michigan's Chicago shoreline Wednesday. Frostbite warnings were issued for parts of the U.S. Midwest as temperatures plunged. Joshua Lott/AFP/Getty Images hide caption
Esther Ngumbi, who now lives in Chicago, gets a taste of the big chill. She grew up in Kenya, where 60 degrees was about as cold as it got. Alex Mutiso hide caption
People bundled up against the cold in downtown Chicago on Sunday. Forecasters warned of dangerous weather conditions across a swath of the U.S. over the next several days. Nam Y. Huh/AP hide caption
A man walks through the streets of Boston on Thursday as snow falls from a massive winter storm. Schools and businesses throughout the Boston area were closed during the storm. Spencer Platt/Getty Images hide caption
Record cold temperatures are gripping much of the U.S., including subzero temperatures in Chicago on Tuesday. Scott Olson/Getty Images hide caption
Pedestrians brave the cold during their morning commute on Friday in New York. Arctic air and bitterly cold wind is moving across the Northeast, plunging temperatures into record-low single digits, accompanied by subzero wind chills. John Minchillo/AP hide caption
At the Australian Bat Clinic in Queensland, 15 baby flying foxes (bats) were lined up and ready to be fed Thursday. They were brought there to get out of the extreme heat, which has killed hundreds of thousands of bats. Trish Wimberley/AP hide caption
Hell, Mich., is embracing its frozen fame. The town's Facebook page now features this photo from 2003. Keasha LeClear-Morse/Facebook.com/gotohellmichigan hide caption
A man walks through a steam cloud in frigid cold temperatures Tuesday in Manhattan. Brendan McDermid/Reuters/Landov hide caption
Robert Vick, in an undated photo provided by Kentucky Department of Corrections. After a cold night and day, he asked to be put back in prison. AP hide caption
Ice has built up along Lake Michigan in Chicago as temperatures have plunged in recent days. A dip in the polar vortex is to blame. Scott Olson/Getty Images hide caption
This woman in Chicago was well protected from the cold on Monday. Kamil Krzaczynski/EPA/Landov hide caption
Dealing with it in Detroit: A woman protects her face from the cold on Monday. Joshua Lott/Getty Images hide caption
If you're in a blue or purple zone, you're going to be cold tonight. National Weather Service hide caption
An image from the animated look at how cold air has spread over the nation. NOAAVisualizations hide caption
Julie Caruso of Akron, Ohio, was wrapped up Tuesday as she waited in line for a White House tour. It was well below freezing in the nation's capital. Temperatures were even lower in other parts of the nation. Kevin Lamarque/Reuters /Landov hide caption