Most of the stories I’ve heard about passengers riding the Chicago Transit Authority without pants on are disgusting and disturbing. That (probably) won’t be the case for passengers riding the Red Line train in their skivvies on Sunday, January 11th though — it’s time again for Improv Everywhere’s No Pants Subway Ride.

Have fun being cold, I guess.

Once a year, Improv Everywhere inspires people in the world’s largest cities to ride public transportation without pants on. Spawning out of New York, over 50 cities officially take part in the yearly No Pants Subway Ride, including Helsinki, which I constantly forget is a real place.

(Sorry, Finland. Geography is one of my many weak points.)

Chicago, whose citizens never pass up the chance to take their clothes off — especially when its freezing out — is obviously participating.

The plan: On January 11th, hop on to the train (minus your pants) at noon. The official Facebook event instructs people to meet near the Loyola Red Line stop, specifically the “roof deck of the parking garage at 1210 W Arthur above the CVS.” Expect to ride from Loyola to the Roosevelt stop and back. Not in Chicago? Find instructions for other cities here.

According to a media representative with the CTA, the No Pants Subway Ride isn’t breaking any rules. “There’s nothing in our ordinance … that would prevent someone from riding our system without pants as part of the ‘No Pants Subway Ride’ event. Therefore, those boarding trains in their underwear as part of this event will be treated as any other fare-paying customer.”

Sadly, your conductor doesn’t get to participate in the fun: “There is a required uniform for CTA bus and rail operators and customer assistants, which would not allow their participation in this event.”

Why participate in the No Pants Subway Ride, especially in the middle of winter? It’s just supposed to be a fun, silly prank, says the Improv Anywhere website: “The idea behind No Pants is simple: Random passengers board a subway car at separate stops in the middle of winter without pants. The participants behave as if they do not know each other, and they all wear winter coats, hats, scarves, and gloves. The only unusual thing is their lack of pants.”

By the way, in case you’re worried of subzero temperatures blowing up your you-know-what, Sunday’s weather forecast is a lot less brutal than the last few days. Currently, there’s a predicted high of 28 degrees.

Last year, WBBM’s Nancy Harty saw hot pink striped bikini briefs, green beer mug boxers and a couple of speedos riding the train.

“But, still, people are gonna look at you and it’s gonna draw attention to yourself,” one rider had commented.

No kidding.

Below, you’ll find a video of last year’s group doing the hokey pokey at what appears to be the Roosevelt station. Is that a real priest doing the hokey pokey? And which passengers had no idea about the No Pants Subway Ride? Everyone appears to be hokey pokey-ing…

Mason Johnson is a Web Content Producer for CBS Chicago. You can find him on Twitter.