You can also try configuring your power settings to only speed up the cpu and RAM when needed for processing purposes, throttling it down when not necessary. This will usually help control system temperatures. Don't set it on maximum continual power.
I was having the same problem a week ago, took my laptop at the shop for repairing. It was shutting down after heating up, then I came to know that there was something stuck in the fan, they just fix it and cleaned the fan, now it is okay.
If it is not the problem with your laptop then you ought to apply the paste that is available in the market, here it is somewhat costly but you can check it.
Hope this will help you out.