Question PC crashes under stress - image freezes and audio becomes a buzz/hanging/loop noise (not physical, headphone only)

[Azeew]

I've had this PC for about 3 years. This has been happening for a while, can't say if it was since the very beginning, though.
It only happens when I play extremely heavy games. And I've always thought it was insufficient RAM, since I'm only running 8gb. But now I'm not so sure anymore, and I'm starting to get worried that it could be something more serious. I can play somewhat high-end games pretty well though. Hours and hours of BDO and Sekiro recently, for example. But I've gotten quite a few crashes recently when playing Path of Exile, a game that isn't supposed to be so difficult to run. It happens at seamingly random moments, not necessarily when under the most stress. PoE's latest patch is known to have screwed performance a bit, but still, I'm worried about the fact it crashes. Here are two example occasions when it crashed:

GPU - 82ºC - 63% usage
CPU - 81ºC - 44% usage
RAM - 6893mb

GPU - 82ºC - 97% usage
CPU - 87ºC - 60% usage
RAM - 6017mb

They get pretty hot, I guess, but that shouldn't be the problem, right? RAM is also not so absurdly high that it should crash. I can't try memtest86 for now, but Windows's memory test showed no problems.

My specs:
Intel Core i5-8600K
Nvidia GTX 1070-Ti
Kingston A1000 NVMe PCIe M.2 240GB
Crucial UDIMM DDR4 2400 C16 1x8GB
GA-Z370M AORUS Gaming

Thanks a lot in advance.

 

[popatim]

87c at 60%, what cpu cooler do you have?

 

[Azeew]

87c at 60%, what cpu cooler do you have?

It's a very cheap, generic one. Cooling is most definitely not my PC's forte, haha.
And I'm not sure how much that matters, but it's like 30-40ºC where I live right now.

Do you think it could be related to the issue? Or if it's a big deal in general and should be addressed regardless?
I'm trying to save money, though

Thanks!