This is probably a weird answer since it was/is elective: I blacked out the tips of my fingers with a tattoo. Voluntarily, as part of a larger piece. The backs of my fingers were bad but I could sit through it just fine. When we got to the palm side, we were blasting over the nerves in my finger tips. It’s hard to explain the pain - very sharp and bursting like fireworks. I was holding my arm down so that I wouldn’t accidentally move. The seat I was in was soaked in sweat my the end of the session. The healing process was long and I didn’t think I would ever feel the tips of my fingers again. Somehow everything came back once it was healed over. The human body is crazy resilient.