Those are maximum on-die values and may not be the same as what the BIOS states (some recent motherboards have listed anomalously low temperatures). Cooler is better even if the CPU can take it - it increases the life of the chip. The fact that it's quitting indicates that it's not happy. :-)
[link|http://www.xbitlabs.com/articles/cpu/display/athlon-xp-2200.html|This] page talks quite a bit about Athlon XP temperatures in comparison with the P4. [link|http://www.cpuidle.de/|CPUIdle] is some software that claims to reduce the CPU temperature by telling it to idle when it's not working. No idea if it works, but it might be worth trying.
Cheers,
Scott.