Yeah, my machine runs hot, as I can hear the fan cranked up while playing it.
I finally tried this out properly online instead of in practice mode. It's not as hard as I thought it was, though I was playing easy mode. I was concerned about not getting used to the directional movement and firing at the same time, in addition to changing weapons and using items. I hope I'll get better in time.
Check me out:
Steam Community :: Alien Swarm Stats :: [TFP] Baraka_Guru
Oh, and it's a beautiful-looking game, and the sounds are great too. I especially like the echoing/diminishing sound of gunfire/voices when your squad moves further away from you.
Pretty cool lighting/alien blood splatter effects.