I did that with a really hot rock once. We were out on the Blackfeet Indian reservation in Montana and after a long day of seeing patients at this temporary clinic we set up (we were students on a mission trip of sorts... 19 students, 3 clinical days, over 2,000 patients seen!) we had a nice campfire going at our camp. Someone moved a really toasty rock out of the fire and about a foot away from it. I came up and thought "Gee, that's a nice rock. It would make a great addition to this fire ring..." and picked it up to move it. I was already dropping it by the time my brain registered what was going on (thank God for reflexes!), but I had trouble sleeping that night because of pain. To my surprise, though, I woke up the next day with no pain, just a thick, leathery feeling on my skin (from the nerves I torched, probably). I was lucky!