The above answers are great already!
If there is dust, do try to clean it after referring a good tear-down/disassembly guide.
If there is still extreme heat (this may even be caused due to gaming for a longtime on a laptop with games that need powerful specs but your laptop may just have the minimum requirements - I have had this issue too), either try to buy a cooling pad (which doesn't cost too much and works well for me) OR Build a Cooling Pad (there is a YouTube video out there explaining how you can make one with an egg tray!)
Hope your laptop learns to chill! :)