I got my first flat today, but I don't know how it happened. I rode the bike to the light rail station, and put it in my bike locker. Got on the light rail, went to class, and then back to the light rail station. Got to my bike, and found out the rear tire was flat. It was fine when I got there, but not so when I went to leave. Total time in the locker is about 2-2.5 hours.

Is it possible that there was enough heat built up in the locker to cause a flat? Or would that require an extraordinary amount of heat to cause that?