The absolute best way is to not fall into the trap of playing new games. Stick to games that are 4 years old.
If you don't adhere to getting and playing the latest games, a few things will happen:
1) going to a friend's house to play a game or two will be simply amazing and fun.
2) as you play out the games from e.g., 2012, the 2013 games will be new.
3) you can avoid bad games because you can ask people which have the best playability.
4) you can acquire them for lower cost through STEAM or purchasing used, a few years after the release.
Alternatively, pick up and play games that are low of graphics... e.g., 8 bit armies or something, to tide you over.
The only other advice, which you like already do -- ADD COOLING! what can you do to help it out? Take cover off and point three fans at it? Vacuum? Other? play in a cool room?