From chadseld at macnn forums:
From what I can gather, reading about the MBP thermal issues, here are the good/bad ranges:
65c-70c idle & 85c-95c under load
40c-50c idle & 60c-70c under load
In order to cause a kernel panic, I think the CPU needs to get above 100c. Also, these numbers are from the MacBook Pro. I'm not sure how the different case in the MacBook affects things. I.E. the good range may be higher for the MacBook because the plastic case doesn't conduct heat as easily?
From Draco at macnn forums:
Btw, I don't know if anyone will find solace in this information... but I thought it was worth knowing about since everyone is up in arms in how hot this thing gets:
"Apparently Core Duo CPUs are rated to 100C, over that data integrity suffers and at 125C they have a hard thermal shutdown feature to protect the CPU from actual damage.
They throttle to keep temps under 100C to ensure data integrity.
Throttling can also be used as power saving strategy.
Temps under 100C under load are within spec."
DISCLAIMER: I do NOT recommend that you disassemble your computer if you still want your warranty to be intact. Make sure you have the expertise to work with electronic components before opening the machine.