Some would call me reckless, but I don't wear any safety gear. I wear glasses to see, but other than that, just my normal work-type clothes. Cotton is best. Synthetics will melt and stick to your skin along with the lead in the case of a spill.
One thing I do that most don't, is I cast standing up. This is so I can "Get outa Dodge" should something happen. I just can't imagine a lap-full of molten lead. I prefer my pants to be over the tops of my boots. Don't need to fill them suckers up in a spill either.
I've never had anything more than a splash or two in many years of casting. "Touch Wood"!