Heating problem with my my Laptop. What to do?

I have i3 Lenovo laptop, and my laptop is continuing on 8 to 9 hours, and I'm facing the problem of heating…

Check processor

How long do you have it? There's always a layer of thermal grease between CPU and cooling. As it gets old, the air start to fill more and more space comparing to thermal grease, that's why cooling doesn't work properly anymore. You should clean CPU from old grease and put a new one.

Buy a laptop cooler. The laptop sits on top of the fan and it pushes cool air onto the laptop, therefore cooling it.