Apple - Support - PowerBook - Care and HandlingI am presently running at 111 Farenheight.
Sometimes it's hotter; it leaves spots on my legs that look like sunburn.
The bottom of the PowerBook case functions as a cooling surface that transfers heat from inside the computer to the cooler air outside.
Contrary to popular belief and use, they are not 'laptops'.The bottom surface and some areas between the keyboard and LCD hinge of your Apple portable computer can become very warm after extended periods of use.
This is normal operating behavior.