in many reported cases of laptops overheating. Does the fan appear to be running correctly?
It's surprising how much rubbish can accumulate inside a laptop after a few years use, and I suggest that you give yours a clean.
1. Before you start, turn off the mains power and remove the laptop's main battery.
2. get a supply of ordinary cotton buds, and buy a can of compressed air - any good computer shop will sell it.
3. Turn the laptop over and remove the small covers you'll find there. Carefully check for dust accumulation inside, but DO NOT touch the components with your bare fingers.
4. Use a cotton bud to remove any obvious dust or fluff, and then give the insides a blast or two of compressed air. Don't hold the can upside down, or you may swamp the components with supercooled liquid. Replace the covers you removed.
5. Now check the fan outlets and inlet grille. Remove as much dust/fluff as possible with a cotton bud and repeat the compressed air treatment. When cleaning around the fan itself make sure to use a cotton bud to hold the fan blades steady before blasting with air - otherwise you will set the fan spinning at very high speed, and may damage the bearing.
Once you've finished, restart the computer and listen to check that the fan's running correctly.