You accidently locked your clothes and towel in the locker.

You finish taking a shower and you realize that you stupidly put your towel in the locker. You walk back to the locker and as soon as you see the lock you realize that you left the key in your trousers. These are old steel lockers and you have a sturdy lock. You aren't getting the locker open on your own.

You look around for something to cover yourself with. This is an old building and is pretty spartan and not well maintained. There's nothing in here that would work. The toilet doesn't even have toilet paper.