I have a stupid cubby in my desk that I alway run with the door open. I decided to stress test the computer with the door closed to see what happens overnight. Here are the results. When i opened the door to the cubby the air was really warm.
http://img329.imageshack.us/img329/7034/ss0ei.jpg
http://img329.imageshack.us/img329/7034/ss0ei.jpg