Going camping calls for creativity. You oftentimes are without the luxuries of home life. Electricity is far away and ovens become a mere memory. In those circumstances (if you did not come prepared) you have to get creative if you want to eat. These people found a mailbox (no one knows where) and somehow turned it into an oven that they used to cook and heat up water during their trip.
All it took was a metal mailbox, some pieces of wood, and a flame....and then these people had themselves a nice, hot oven. No one can say whether or not it actually worked though.