How would you keep it burning? Drop in lit charcoal briquettes? BAD IDEA! It could kill you! Dude, I'd be so worried about carbon dioxide/monoxide poisoning. The more air tight, the more danger. Long ago a friend's cousin and a couple of other kids stole a cylinder of nitrous oxide and opened it in a VW. The kids passed out from lack of oxygen and I believe that 3 of them died and the fourth had severe brain damage. Yeah, that was nitrous, but CO2 and CO can do you in just as easily. Every year there is some idiot heating a boat or small cabin with a BBQ or hibachi and dying of CO poisoning. Please think things out a bit better! - Granny:hippy: