hmmm, there are two things that come to mind, Either a heat issue, or a video card issue.
It's best if you give us some more info on the problem, that's a little vague.
Does this happen in a lot of programs, or just esf? What kind of video card do you have? Is your computer overclocked?
Well, for now, try these solutions.
#1 Clean all of the dust out of your computer using compressed air in a can.
#2 make sure your fan(s) are working properly
#3 download the latest drivers for your video card
**EDIT**
If you clean the fans when using the compressed air, make sure not to make the fans spin too fast, it can possibly burn out it's engine.