Fortunately, in most cases, there is no reason for you to panic and I am here to share with you some methods to try to fix this problem when your computer shuts down when you play Diablo 3.
First, you should try the official method recommended by Blizzard on the official Battle.net forums:
“Blizzard and Nvidia are looking into this issue, and we’d like to get some heat numbers from you so that the engineers will have a clearer picture of how things are breaking down. To check where your heat levels are at when the blackscreen occurs, please follow the below instructions.
Heat Monitoring Instructions
1. Download and install any Hardware monitoring program such as CPUID’s Hardware Monitor: http://www.cpuid.com/softwares/hwmonitor.html
2. Startup up the Hardware Monitoring program.
3. Expand the section you want to see (Video card in this case).
4. Start Diablo III in Windowed mode, and move the windows so you can see the Video card temperature while Diablo III is the active window.
5. While playing Diablo III pay close attention to the temperature of the video card.
6. Write down the max video card temperature.
Alternative: If your computer only blackscreens in Fullscreen mode, just start up the monitoring program before you begin playing, and after the blackscreen occurs alt-tab back to the monitoring program and check the maximum video card heat level.
**Note** Each video card has a different temperature threshold, and where one video card may black screen at 80c, another may black screen at 100c.
WORKAROUNDS
After you get the needed data, try switching on Vsync and dropping your “Foreground FPS” to 40 in the options menu. It doesn’t work for everyone, but it may help some while the engineers work on the issue.
Another possible way to fix Diablo 3 overheating problems that shut down the computer:
If you have a vid card that has an Auto setting for fan control, DO NOT USE IT!!! Manually set the fan speed for your vid card to 80 to 90 percent, remember, you can never have too much fan! I had this same issue with StarCraft 2. Everytime SC2 went to a cut scene the card would over heat because the auto setting on the fan would drop down to minimum during the cut scene and the card would get hot and close the game. I took the fan off auto, never happened again.
So there you have it, two ways to find a workaround for the overheating problems in Diablo 3. And if this solves the problem, then you know that you are ready to catch up with some speed leveling in Diablo 3. Good luck!