Got some questions 4 u janpatz1983, do you use more than one anti-virus/spyware in real-time? What were your temps about the time it crashed? In a graphics intensive game, heat is notorious for crashing computers. I play BF3 & 4 and I've crashed several times over heat. So much so, I've went to modifying the cooling on my video card. It's an HD7950 3gb made for BF3 and overclocking. My temps were soaring past 86c. Manufacturers say they were made to take higher heat and that may be true.
Fact is, heat slows the flow of electrical current and mobo/video cards have fail/safe protections built in to slow down processing (to prevent crashing due to heat), actually dropping your frame rate (fps). My friend has an Nivida GTX760 4gb and his temps are at 92c. He says it's been over 100c. That's hot.
BF3 & 4 are graphic intensive games which take a lot of processing power to resolute the huge maps. They produce the most heat on my computer.
If you have other programs running while you're playing BF make sure they're turned off. Defragging and removing spyware, also helps.
Here's a little weird thing I discovered about ASUS boards and since Asrock is affiliated with them, yours may have the same feature. In the Bios there's a surge protection program that triggers when you draw too much power. The techs at Asus said to disable it because it's pretty sensitive, plus if you have existing surge protection built along the current path (from UPS unit to psu to mobo) it's not a big necessity. It's been triggering computers to shut down and restart from boot up and it probably can be cured by a bios update or simply going into the bios and turning it off. Hope this helps.