crash PC in gameplay

My PC build: AMD Ryzen 7 3700X 32GB RAM AMD Radeon RX 7900XT graphics. For the first time, my PC suddenly turned off after about 20 minutes. It looked like it was overheating. The PC would not turn on with the classic button or the restart button. I had to turn the power supply off and on. After turning it on, I turned on the temperature gauges and turned on the game. The game played for another 2 hours. The next day I turned on the game again. During the game, the temperature remained +- stable for the processor 65, the graphics 50, and after about 1 hour, the PC turned off again and would not turn on again with the classic buttons.