Severe lag in games, overheating?

I play World of Warcraft and I've been successful in getting it to run on my laptop in the past. I used to raid karazhan on my laptop all the time.

I know the system requirements of the game have increased since then but I'm not sure if that alone can explain the problems I'm having.

Running around the world is usually okay, my problem occurs when I'm in a 5-man dungeon. The game will be running slow but playable and then all of a sudden everything on the screen will freeze and stay that way for maybe 10 seconds before resuming.

Since I play a healer this generally causes everyone in the instance to die when this happens so it's extremely annoying.

I did upgrade my laptop from a 1.4 banias to a 1.7 dothan, I'm wondering if what I'm experiencing is simply overheating? If the CPU is getting hot enough to start throttling that would seem to explain the issue I'm having, though not sure what the solution would be at that point. I've used one of those ~$10 laptop cooling pads in the past but I'm not sure how much good those really do.