Both of my last two laptops, HP Pavilions, slowly overheated and one died after only a year. The next one got taken to a local computer repair store and was opened and cleaned out thoroughly ever 18months or so. I have/had six dogs and quite a bit of dog hair got in, but worse, the very small dander (dead skin flakes) got through the filters and decreased the efficiency of the cooling system. I aslo kept the computer on a cheap ($20)cooling pad with fans to intercept the worst of the crud.
This sort of thing may, or may not, be your problem.