Why is my keyboard getting hot

First run some diagnostic software like Speccy or HWMonitor to check if the temps are higher than they should, for reference take a look at the values showed in this full review of your laptop ("Temperature" paragraph). In this case, aside from keeping your laptop on a solid, flat surface while it's operating, here are some possible solutions to the laptop's oveheating problems:

• check if the fans are working properly, basically you should feel with your hand they're effectively blowing hot air out of the chassis, a software like HWMonitor or speedfan will give you real-time info on the system's fan speeds
• if the fans are constantly spinning without issue and temps are still too high, air vents could be clogged: assuming that the warranty period has expired, I suggest you turn off, open up the laptop (with all due precautions) and remove all the dust from the inside (refrain from using a vacuum cleaner or air can, use instead an anti-static brush or a dust blower) , especially the air vents (and filters) and fans; while you're at it, replace the thermal paste if needed.

Other tricks that will help you keep your system cooler are:

• adding a cooling pad to get better airflow
• tweak the performance settings from the Power Options menu
• as suggested by @komota, anti-spam/virus/malware software will help you prevent CPU-intensive unwanted apps to run on your PC
• any missing or worn rubber spacers under the laptop should be replaced

Finally, to get info on your battery's health on Windows, type the "powercfg /batteryreport" command, then simply open the newly created report (it's in your home folder). For more information, check out this article

Hope this helps

Cheers