Pc keeps crashing when playing games and occasionally restarts itself

Hi just seeing if anyone can help, my specs are.

Aorus b550 pro AC motherboard

AMD Ryzen 7 5800x 8-core processor

Nvidia GeForce RTX 3070

Corsair RM750 power supple

32gb ram

After a while of playing any game my game will either crash or my pc will shut off and I’ve got no idea what’s going on?

Cheers