All kernal 41 tells you is it lost power and you know that because it shutdown and restarted.
Temps - always worth a clean out of your machine and graphics card een if you think its not that.
Memory - rum a memtest
Disk space is there enogugh space on the partition - make sure you have at least 20% free space.
Drivers the usual advice is to update to the latest - however I have a couple of games that will only run on old drivers.