Based on your description, this sounds like a classic thermal protection or driver instability issue specific to the high GPU/CPU load during gaming. Your theory about temperature is very plausible.
First, ensure your graphics drivers are completely updated. If the issue persists, try monitoring your GPU temperature during a gaming session using a tool like HWMonitor to confirm if it’s throttling.
A temporary workaround can be to limit your in-game frame rate slightly to reduce the continuous load. For a different kind of challenge while troubleshooting, you can always take a strategic break and check this for a change of pace.
If the problem is consistent, contacting Mind support with your findings would be the best next step, as it could indicate a hardware fault.