I have an '09 MBP 13" that I run in clamshell mode at my desk using TwelveSouth's BookArc stands. I have a cabinet on my desk that measures 15" high, by 20" wide, by 9" deep. Would it be safe to place the MBP (clamshell) into this cabinet while in use? Or would it be too hot? the cabinet does have doors on the front of it....