Knowing that you are on a laptop also supports my thoughts on overheating. I would try getting a program like afterburner or somrthing that will allow you to manually set your GPU fan speed. Even motherboard controller may have it. Set the manual fan speed to 100% you will hear it crank up to full speed. Go in game and see if you have any issues.

Eport back after trying that if you like and we will take it from there. Keep note of how long you can play before problems come back (if they do).

Also if you plan on gaming with a laptop for any extended period I would highly suggest getting a cooling pad. For example the CM strom sf-19.

On a side note, please remember I am not a professional in any way. Simply another player trying to help out. Take my suggestions if you like but do so at your own risk.