Why does my laptop keep overheating even when I'm just browsing?

I've noticed my laptop gets super hot and the fan goes crazy loud even when I'm just doing light stuff like browsing the web or watching videos. I cleaned out the vents recently and made sure nothing is blocking airflow, but it still feels like a mini heater. I checked task manager and there’s nothing crazy eating up CPU or memory, so I’m stumped. I also tried updating the graphics and chipset drivers, but the problem persists. Battery health looks okay too. It’s an older laptop (about 4 years), so maybe thermal paste needs reapplying? Not sure if that’s something I can do myself without risking damage. Has anyone else dealt with this? Any tips on diagnosing overheating issues or cheap fixes before I consider more expensive repairs? Would love to hear your experiences or ideas!