As simple as putting thecomputer in box where the air that comes out of the laptop , do not came back....
when the laptop is in a desk, this warm air maigth enter again in the computer , or not came out totaly , or just makes a hot enviroment around the laptop ...
So get something like a box (which size migth be smaller than the laptop) , with holes at the side , and without a top... so that the air comes out of the laptop , and gets out for the holes ....
This "box" could be made of wood , to be less unnormal xD
This will improve your over-heating resistance :P
P.D.:Sorry about the bad english :S