If the base, or keyboard deck, of your laptop starts getting toasty, it’s tricky to find the culprit. It could be a result of demanding programs that require a lot of computing power or just a ton of background activity. Another issue that could heat up the chassis is high ambient temperature, which can either be addressed by moving to cooler environs, using a fan, or just allowing base airflow. Clogged vents and fins on the cooling fan(s) can also cause the temperatures to rise, especially on gaming machines where the processor and graphics engine combo generates more heat.
If cleaning them doesn’t solve the battery heating issues, try to step down the performance mode or set the system configuration to a lower profile. If neither cleaning nor software tuning solves the heating problem, the only other option is to look at battery assembly. Try draining the entire battery, charging it again, and using the laptop without the charger plugged in to see if the thermal issues persist. You should pay attention to the physical shape of the battery for swelling or bulging.
Sometimes, the bulging is so severe that it can also force open the chassis on the side or the base. In either case, if the heating problem persists and you see any signs of physical damage, you should immediately get it replaced at a service center. Do keep in mind that swollen batteries are extremely hazardous, and fire-related incidents are not unheard of.
