Good thing. Welding arcs give off UV and Infra red rays. Usually, all you get is a sunburn, But repeated prolonged exposure can give you skin cancer.

A big thing to watch out for is arc flash. Basically that sunburn you get on your skin, happens to your eyes. They keep huting, and hurting, it feels like you have sand in them, and they are very sensitive to light, and water like crazy. I have only had a couple of mild flashes so far, but I do know of people that have taken a week off for a severe flash. Avoid it at all costs.