I've reheated pizza using tinfoil and a small space heater before.
When I was little and had a few friends over my parents ordered pizza for us but made it clear that we couldn't have any food after midnight. 1 am rolled around and the three of us were hungry. Since my parents kept their door open at night they could hear anyone using the microwave or toaster oven. Clever as we were, we decided to make a ninja run for the leftover pizza. They grabbed the pizza box & 2 liter and I noticed the tinfoil sitting out and suddenly it hit me. I grabbed it getting a weird look from them and we made our way back to my room using metal gear stealth tactics. They thought I was a dumbass for getting the tinfoil and were complaining that the pizza was cold. Then I pointed at the little space heater that sat in the corner of my cold ass room and they got it! I made a little tinfoil package, stuck the pizza inside, attached it to the front of the heater and cranked that little thing all the way up. 20 or 30 minutes later we had some kick ass toasty Macgyvered pizza.
