I charge mine in my shop on top of a lumber pile....I keep marshmallows and some nicely carved sticks next to it in case of a fire. Maybe I should get some hot dogs too? Only joking. I do charge them on a wooden bench though. I keep telling folks this......because it's true.......follow the directions exactly and you will be fine. I know there are bound to be a few mishaps even when following directions. It's always good to be prepared.....hence the marshmallows