Well for starters, Games usually one of the only things that test your systems CPU higher than most applications.
Of course encoding movies etc. use lot of CPU.
My old pc use to over heat playing counter strike source and only counter strike source. Which turned out to be heating prob.
Graphics card was getting to hot along with my processor
P.s
Can u provide the full spec of your laptop or link to your laptop or the make and model of your laptop.
thanks