Apparently, MOST people with AS are LESS sensitive to a lot of types of pain.(generally what NTs would consider painful) I am that way also. When I was in about the 2nd grade, I was actually distracted for a time, and there was a hot soldering GUN(the kind with TWO connections on the gun side, and the tip covered about 2" by 3" with a tip that was perhaps 1/4") underneath my arm. Something went wrong with that stupid gun. It stayed ON, it burned the carpet, and the gun ITSELF melted(The green plastic case warped and the side on the rug burned)
BTW the gun looked SOMETHING like this:
http://tucson.craigslist.org/tls/666081482.html
(Mine was cleaner, and kind of green plastic with a black trigger, but a craftsman)
Anyway, It seared the skin on my lower right arm(So you could see a welt in the form of the "tip"(The WHOLE thing from solder end to the gun)) I didn't even know my arm was there until I saw it. I had NO discernable pain, and today you would never know it happened!
Of course, like 9 years later, someone tried to bug me by burning me with cigarette butts. I ignored it. I told everyone that I had hot oil spilled on my arm. Still, no special treatments, and still fine.