Welcome to the Powerbook where thin means hot! There are special laptop pads that you can get to dissapate the heat from the metal case which will help. In general, the Powerbooks run within spec, but heat and components do not mix, so I’d suggest one of the pads. Of course, the heat is being sucked out of the components and into the metal casing and then the pad helps pull the heat from that as well without blocking vents or air circulation. Do a search on some sites like Clubmac, and if not there, try Google.