Is it safe to run a heavy game in a non-gaming laptop?
All modern PCs have some means of protection systems that will prevent your machine from running in unsafe temperature modes.
You can check this shutdown on overheating thread on Intel's forum for the details.
So, you are safe, until you do some overclocking and deliberately disabled safety features.
P.S. If you are still paranoid, check metals melting points, they are mostly in hundreds degrees of C, so it's safe to assume that your motherboard soldering won't start to melt before your keyboard, which you would easily notice.