Do your best to clean dust from the vents. It likely will not much but it is easy and costs you nothing. If that does not work then you have a more serious problem.
I am going to guess the real problem is the thermal paste has dried up and needs to be cleaned off and replaced. Thermal paste dries up over time and when that happens it can no longer transfer heat. The older your laptop is the more likely this is the cause of overheating.
Replacing thermal paste in a laptop is not something I recommend for the average user since it involves taking apart your laptop which takes a lot of time an patience especially if it is your first time doing so. It would also be wise to document, take pictures, or record video while taking apart a...