NEW YORK (CBSNewYork/AP) — Some New Yorkers braved extreme cold with bare legs Sunday afternoon as they took part in the No Pants Subway Ride.

This was the 17th annual edition of the event, where fellow transit users strip down to their underwear and get on the train.

Participants took part even though the air temperature reached only 18 degrees at Central Park on Sunday. The overnight low Saturday into Sunday was a mere 5 degrees.

PHOTOS: 17th Annual No Pants Subway Ride

No Pants Subway Ride

Participants in the 17th Annual “No Pants Subway Ride” travel in the New York City subway on January 7, 2018 in New York.
The “No Pants Subway Ride” is an annual event started in 2002 by Improv Everywhere in New York, the goal of which is for riders ride the subway train dressed in normal winter clothes without pants while keeping a straight face. (Credit: TIMOTHY A. CLARY/AFP/Getty Images)

The event, organized by the Improv Everywhere comedy collective, started in 2002 in New York with seven participants.

No Pants Subway Ride

Participants in the 17th Annual “No Pants Subway Ride” travel through a New York City subway station on January 7, 2018 in New York.
The “No Pants Subway Ride” is an annual event started in 2002 by Improv Everywhere in New York, the goal of which is for riders ride the subway train dressed in normal winter clothes without pants while keeping a straight face. (Credit: TIMOTHY A. CLARY/AFP/Getty Images)

Pants-less subway rides take place every year in dozens of cities around the world – all at 3 p.m. local time.

Participants are told to get on trains and act as they normally would and are given an assigned point to take off their pants. They’re asked to keep a straight face and respond matter-of-factly to anyone who asks them if they’re cold.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)