Batteries (and phones) get rather hot while charging. Putting it under a pillow while charging is asking for trouble. The heat has nowhere to go -- especially if it was a high-current quick charger, like what comes with expensive smartphones.
PEBKAC, for sure. But easier to blame the technology, eh?
I have installed electrical outlets at work when the power could not be cut -- just wear appropriate rubber gloves. Another rule I learned when working inside operating high-voltage equipment (such as when tuning it) is to keep one hand in your pocket, so the electricity cannot pass between your hands into your heart. Stand or kneel on a
rubber mat on concrete floors, also to prevent an electric path through your heart. Such rules were taught to children back before ambulance chasing lawyers got to make the rules...
Idiocracy is on the rise. Now, where did I put my
Brawndo?