I myself went trough the "overheating hell" during 2 years ; my old laptop (2,2 Ghz) sounded like a vacuum cleaner when I tried to render things and it crashed more and more often...until I managed to buy a new laptop. (Dell Inspiron 6400 Double Core Centrino) Now it's  like a beautiful dream to render; the processor keeps a temp about 25 C  ( when I do an intensive rendering) instead of 70 Celsius as on the old one; I just can't believe how large the difference is...I you have the possibility then buy a new baby with a Centrino Proc. so that it won't overheat and crash any more!