Is there anykind of dampening material that will NOT absorb heat, and keep the PC cool, while lowering sound levels by alot. I need some of that. How would I install this stuff?

Tyan trinity 400 s1854
Celeron 400 PPGA
96mb pc100
TNT2 Creative
SBlive Xgamer
Win98 First Edition
Maxtor 8.4gig