I'm looking for a reason of high temperature of cpu

Check to see where the air vents are on your laptop. Don't allow them to be blocked. For instance, if they are on the bottom then don't place the laptop on a soft surface, like a blanket. A hard, flat surface is best. If the laptop is older, maybe it needs to be cleaned out.

A lot depends on what you're doing. Many laptops are not meant for gaming.