Thanks PSM. That is what I was thinking about. It says it burns 10 hours so I was only about half right.
I agree they might be a good item to have handy.
One thing about the charcoal is they can sit on a shelf for ages and still work when you need it.

SFAIK the sticks were just compressed charcoal. The fact they were insulated helped them stay lit. I can remember stubbing the sticks out when done with the warmer and relighting them later.