What's the most ridiculous thing you've managed to hurt yourself with?

My son once put rare earth magnets up his nose, one in each nostril. Predictably enough, they viciously pinched his nasal septum. His efforts to get them out just drove them up further. Even an ER doctor failed to get them out. After he had passed a long, miserable night in their cruel embrace, we managed to lure them out with another magnet.

At work, I once had to zest a whole crate of oranges. The orange oil spraying up onto my forearms over a couple of hours gave me a chemical burn that made my skin blister and peel.

Your turn.