This isn't the first time I have burned myself but it has been a while. The way I did it was one of the doors on the truck I drive was stuck. I got out to help get it open from the outside. When I pulled on the door it started coming open and my hand slipped off. Because of the motion my arm got against exhaust pipe which has no heat shield. The tempature of exhaust pipes on an 18 wheeler tend to range from 200-500 degrees depending on what the truck is doing at the time. I have a temp gauge for my exhaust and it ranges from as little as 300-1200 degrees. If it gets much above 1200 degrees it can start melting stuff.