You could buy a laptop cooling pad but that won't fix the problem, it'll cover it up but the laptop might not shut down as often, especially if you don't do any troubleshooting on it.
I would take the model number and put it in the YouTube search area, something like "repairing an Acer V3-551-8419" (without the quotes) and see if you can find a guide on there to dis-assemble the laptop and clean it out, or a guide similar to that model laptop.
I did a complete dis-assembly of a Dell 17" gaming laptop because of overheating and the cooling fins and the cooling fan were completely full of dust bunnies.
While it was torn apart, I replaced the thermal paste on the graphics card too.
Everything is back to normal and it's been running...