Had the same issue. Ryen 7800x3d, rtx 4070, 850w psu. When I loaded this a save or entered a video, randomly, oops PC shuts off. Cpu temps high but ok on overlay so if the spike happened it was fast. No GPU temp issues.
Solution was to go into overclock settings in bios and put a max on the temp for the chip. I put it at 65 no issues now. I'll try 75 or 85 maybe after a few weeks. System seems to be limiting clock speed on cpu to keep it in check. Performance impact negligible.
Others I have read achieve the same by limiting the wattage on their CPUs in bios or by enabling eco mode on certain motherboard/cpus.
I tried eco mode in ryzen master. It did not work. Only bios did for me.
This leads me to believe something going on with game causing cpu drawing too much power and/or hitting high temp. Probably the former as there did not seem to be any metallic smell and all other temps were great.
