Dell XPS 15z overheating and shutoff during starcraft 2 gameplay.

I purchased this laptop ,Dell XPS15z on December 2011 in Malaysia. I used to be able to play Starcraft 2 although it is a little warm on my left side of the laptop. It is currently getting worse when it just create intense heat and automatically shut down my computer. I even bought a logitech cooling pad n200 but it did not help with my situation at all. Is something wrong with my hard drive??