On this article,  I will  be enlightening you on why your laptop gets hot and possible do-it-yourself solutions for overheating.
Heating on most electronics are mostly normal and this is mostly caused by the voltage and current running through the components or chips of a device e.g after watching television for a while you find out that the screen heats up when you come in contact with it,even your phone heats up when you use it but the hotness is more when you are charging it and using it at the same time. A host of other devices heats up when being used too. 

The processor of a computer is a chip-like detachable/nondetachable component that processes data on a computer. It  is the core component of a computer/laptop and the most current/voltages consuming component on a laptop/computer.  In other words,  it is the part where the most heat is been produced in a computer thats why most processors have a heat zinc over them and a cooling fan mostly on the end sides of a laptop to calm the heat or balance the heat that comes out of the processor. If the fan or heat zinc is bad or blocked by dust particles,computer may malfunction as it would go off during use, hang consistently or become slow also a bad processor can cause a laptop/computer not to display or in some cases wont even turn on. Other components that can cause a laptop to become hot include the Video graphics adaptor (VGA), bad capacitors and diodes. 

In  most cases,  laptop heating up is a very normal phenomenon except it is overheating and causing the system to shut down abnormally or not displaying is when it becomes a problem.
you can prevent your laptop from overheating by not using it on the bed or an any surface that blocks the vent area. Preferably, you can place a big book under the laptop to lift the base up and create space for air to enter and prevent overheating. Charging  and using it at the same time can also cause overheating.

I hope this helps.