It blows air onto it.
It works like this,
You have your video processor/regular computer cpu. Attached to these cpu's are heatsinks (the fin looking thing). The heatsink pulls the heat away from the cpu and disperses it into it's fins. The fans blow air onto the fins of the heatsink to keep it cool.
You should also have case fans. either sucking air into the case in the front or bottom and blowing it out the back or top.