If it's a desktop: 1- Open the side cover and strap a desktop fan to the side of it and start it whenever you run the rig.
2- Apply a new thermal paste for the cpu fan (Or better yet get a new cpu fan and skip step one)
If it's a laptop place a thick book under the cover so the air vents under the laptop can receive more air.
I'm not joking, Trust me. I've had experience with overheating.
Imlunchboxx
give my condolences
thegarbear14
http://www.youtube.com/watch?v=gn F2IoRhqbw