Computer overheats extremely when using 11.10

Hi everyene, I have just upgraded from ubuntu10.10 to 11.10. I found I problem with ubuntu11.10 and it's that the computer temperature goes up to 200degrees celsius in about 15 minutes and just automatically shuts down. Also the fans is extremely slow, I think the it'speed of the cpu is set to max. I can't change it though. On windows xp the computer is fine though. Could someone please help, I'm really worried tat my computer might fry if I use ubuntu. Pleas help