To check for overheating:
1. Download Prime95, FurMark and HWMonitor.
2. Run HWMonitor. Then run Prime95, and when it launches select In-Place Large FFTs. Lastly, run FurMark and select burn in test.
3. Now, look at HWMonitor. You should see your processor temperatures and your graphics card temperatures (and some more). Watch them closely climb for 5 mins. In that time, they will have reached their maximums. Report the temps back.