Many years ago, I bought a breakfast sandwich, I think it was Harvey's but can't remember. It was in a bag and I just threw the bag in the micro at work and pressed reheat and went to my desk for a minute. Next thing you know, the fire alarm is going off and the kitchen was filled with smoke. The bag in the micro was in flames. The Fire dep't came, it was quite embarassing.
The sandwich was wrapped in a thin tinfoil lined wrapper, then put in the paper bag.
Never did that again.