I believe that's called "streaking."
I've done that once.
It was during a PE lesson at a public indoor swimming pool. Most of my classmates as well as our teacher had already gone in the pool. I, slow as usual, was possibly the last one to come out of the shower room and enter the pool area. Indoor pools being noisy and reverberant as they are, I didn't really notice anything out of ordinary and walked calmly towards everyone. Completely oblivious. At some point the noise started to sound a bit unusual and I realized someone is actually shouting.. a few more moments later I realized it's my teacher shouting, and they were shouting at me. My name, yes I heard her shouting my name and I could tell she was looking my way and waving at me. I was dumbfounded. I figured it's got to be because I'm late, though that was weird because I didn't think I was *that* late. I still had no idea what she was trying to say and even if she said it, I couldn't hear it well so I picked up pace and hurried towards that one pool where she was together with all my classmates.
Well, eventually I got close enough to hear what she had to say. I was naked, coz I forgot my fucking trunks. And pretty much everyone in the building saw, heard, and knew. Pointless as though it was, I ran back even though you're not supposed to run at the pool... *Sigh*