...but I know for sure that the 15.2" tBook can get VERY hot but not hot enough to burn someone's clothing
Seriously, though if you read close in Apple Care documents online and also the manuals that came with tBooks CLEARLY they say:
"After extended periods of use, the bottom surface can become very warm. You should avoid prolonged physical contact with the bottom of the computer when it does get warm.
Here are some suggestions for working with your PowerBook to address any concerns you may have with the operating temperature. These suggestions are also applicable to PowerBook G3 Series (Bronze keyboard) and PowerBook (FireWire) computers.
When using your PowerBook, place it on a hard surface, such as a desktop or a tray. A hard surface allows air flow under the computer to dissipate heat. Placing it on a soft surface such as a towel or pillow is not recommended because it does not allow air to flow under the computer.
Turn on processor cycling in the Energy Saver control panel to greatly reduce the temperature of the computer. To further reduce the operating temperature, select Reduce Processor Speed and select a shorter time setting for Hard Disk Spin down, also in the Energy Saver control panel.
The internal fan in the PowerBook G3 Series and PowerBook G4 comes on within a temperature range that is selected to ensure proper operation of the computer.
The PowerBook G3 Series and PowerBook G4 computers comply with the safety standard for Information Technology Equipment, IEC 950. This safety standard is sometimes referred to as UL 1950 in USA, CSA 950 in Canada, EN 60 950 in Europe, and ASNZ3260 in Australian/New Zealand.
There are third party utilities that measure the temperature of a PowerBook. It is important to understand that these utilities are not measuring the external case temperature. The actual case temperature is much lower.
With processor and bus speeds achieved in portable computers today often matching, if not exceeding, those of desktop systems, increased operating temperatures in portable computing products are common throughout the industry."
Also, taken straight from tBook 1GHz manual:
"When using you PowerBook or when charging the battery, it is normal for the bottom of the case to get warm. The bottom of the PowerBook case functions as a cooling surface that transfers heat from inside the computer to the cooler air outside. The bottom of the case is raised slightly to allow airflow that keeps the unit within normal operating temperatures.
WARNING... Do not place your PowerBook on a pillow or other soft material when it is on, as the material may block the airflow vents and cause the computer to overheat. Never place anything over your keyboard before closing the display. This can cause your computer to cycle on and off which may create excessive heat and drain your battery. Never turn on your computer unless all of its internal and external parts are in place. Operating the computer when it is open or missing parts can be dangerous and can damage your computer.
..."
So, according to this if your tBook or aBook gets hot most probably its your fault
As for iBook, it is really cooler but then again it doesn't carry all the stuff that p/aBooks have!
