Consistent freeze-> crash

Hell yall, I’ve been having and issue with my build recently, was hoping yall could help me out. I’ll launch it and go into games like Fortnite, lethal company, war thunder, and sometimes DCS, and it’ll run just fine and smooth for 2-3 hours and then randomly freeze. No inputs recognized, then a minute later both screens go and the computer turns off. Any ideas what could be causing this?

Here’s my specs if that matters:

• asus tuf X570
• ryzen 7 2700 (yeah ik I’ve been meaning to upgrade)
• Radeon 6600xt
• 32gb Corsair vengeance pro @ 3200mhz
• liquid cooler and fans to support
• 750 watt psu
• 1 M.2 500gb drive, 1 250gb boot ssd, and a 2tb hard drive