Can you give me more details regarding the problem? When did it start to happen? Did you make any BIOS update prior the laptop error? If not, then I suggest you to check if the fan is spinning correctly because the most reason for the automatic shutdown of the laptop is the overheating problem. Does the screen show any error code while frozen? Do you get a blue screen? My advice is, if you have any doubts regarding the cooling system of the laptop or the CPU, to bring your laptop to a technician to test it. If you have more than one RAM stick, you could open the laptop /if its out of warranty/ and try changing the sticks.