Watch your temps and for as long as you feel like gaming. I've gamed on laptops for hours and hours and for ones that had issues with temperatures I would just elevate the back feet an inch or so with a book or something on the table to make sure it got more ventilation. Chill pads help too if you can find one where the fans on the chill pad are roughly lined up with the intake fan on the laptop. It won't necessarily force more air through the laptop, but it'll help keep cool air circulating between the laptop and the surface instead of allowing it to just build up shitloads of hot air that just gets sucked into the intake fan.