Games crashing more frequently, could cpu be degraded?

[Deimos Impact]

Games are crashing quite frequently on my computer, especially when I have other applications open. For the last two years my i5 6400 has been running really hot since my case has very little airflow and I only recently replaced the stock cooler with a hyperx 212 which is making the temps closer to 40-50 degrees celsius all the time now. Previously it would often reach into 80-90, even 100, which made me question the accuracy of the program - HW Monitor - but it seems okay. Could these two things be connected? If so, would underclocking or overvolting the cpu help (since I have lots of temperature room now)?

Thanks

 

[lumineZ]

Could be that you have damaged the CPU by running it so hot for long. You can try to raise the volts by 0.050 volts.
DO NOT go past 1.350 is my advice.

 

[Deimos Impact]

I have been running it at 1.1 volts instead of 1.0 for almost a week, and though the crashes are less frequent, they still occur, so I am raising it to 1.15. It's hard to tell if it even made a difference, so I'm gonna start recording when each crash occurs in a spreadsheet.