Now that narf and blanka’s solution for booting Windows XP on Intel Macs is out in the wild and lots of people are experimenting with it, some bugs have showed up. This is to be expected and fixes will be out within the near future. However according to a thread on MacRumors, the current XP install doesn’t include a fan driver, which means your Mac’s fan never goes on. This could cause major problems for those who use their computers hours at a time.
Fortunately Onmac.net has verified that the fans in Macs do work, regardless of which OS is being run:
Fans have been verified to be working, but are generally only audible under heavy CPU load or when the CPU temperature gets very high. There have been some perceptions that XP is running hotter than Mac OS X, but measurements indicate that maximum case temperatures under XP are no greater than under Mac OS X
Thus the rumors of XP melting your mac are not true and there is no harm in experimenting with XP on intel macs should you wish to do so.
News source: Engadget