On Thursday, October 10, 2013 4:00:37 PM UTC-4, iBoaterer wrote:

My brother was was tightening the positive post of his battery with a
ring on. ring is hitting the wrench, he tightens, ring hits the fender
bolt at the same time. It burned his finger under the ring bad enough
that it took the skin with it when he removed the ring.

Should have attached the positive lead first. First on, last off. That prevents exactly what happened.