Mac Pro getting Really Hot

I am running Windows XP on my Mac Pro via bootcamp. I noticed when I go to play the game "Gyromancer" the temperature on the GPU goes up A LOT. The thing is, its jsut a puzzle game, it shouldn't use much processing power at all... When I checked the GPU temp after 2 minutes, it was at 90 Celcius. After 15 minutes of running the game, it was at 104 Celcius. This does not happen only swith this game. Almost any app I run, the temp goes up to at least 80-87 (and those are the lower powered apps).

Does anybody know how to keep this system cool? I really don't want anything fried. Thanks!

Mac Pro (early 2008)
Xeon 8-core @ 3.00
Windows XP via boot camp
6gb Ram
Nvidia 8800GT

I'm running Win 7 and the temp goes up a lot when put a disc in to install programs. I haven't noticed the problem after removing the disc and turning the machine off to let it cool down. I can start it again later and run any app that I want and it doesn't heat up. It also doesn't seem to matter how long I let it sit with the disc in, it doesn't cool down even though I'm not actively doing anything.

Does anyone know how hot is too hot before it gets into the danger zone?