When AC stick welding on an I beam in hot weather I had an arc strike down my forearm that was holding said I beam. My welding gloves and leathers had gotten pretty wet with sweat and lost insulating properties with sweat being conductive. What amazed me was the distance the arc jumped to my arm. My hood was up and I swear it cleared a 3 inch gap. When I popped my jacket off I could see 4 little burn marks where I assume the AC wave changed polarity. My saving grace was the current flowed out my hand and not through my torso and the swinging motion I was making continued and opened up the gap enough to stop the arc. Moral of that story either keep your welding gear dry or don't hold the workpiece (which in this case wasn't an option).