SAN DIEGO (CBS 8) - The cold weather didn't stop dozens of San Diegans from riding the trolley with no pants on.

It's all part of an annual improv event where people get on the trolley and at a designated time they remove their pants, exposing their under-garments.

Participants met at the Old Town Trolley Station on Sunday, where CBS 8 talked to some of them about why they do it.