Mine idles at 40-60c and goes up to 120 when I play something like Dirt 3 or Tribes: Ascend. It's ultra heat resistant, it has like fans and copper tubing on it. You should get that unless you're Amish, they don't like that stuff, they just let their computers overheat.
My old computer had the side off the whole time for extra airing. Once I tried playing Trackmania Nations Forever on max graphics to see what would happen. It didn't lag at all, it just overheated. I touched the graphics card to see what happened ;-;