I am/was red headed, still have the fair freckled skin. Sunburn was definitely a "thing" in my youth when I desperately thought that a burn would turn in to a tan. It never did, of course. 8 years ago, for other reasons, I had my Vit D level tested, and it was found to be very low (possibly because I had bought into the idea that fair skinned people should always use sunscreen). Over time it was brought up, and I have been a bit obsessive about keeping it up: supplements winter and summer; half strength in the summer with full body noontime sunbaths whenever practical. I am very aware of what my skin will withstand in the way of sun exposure, and haven't had a sunburn in at lest 8 years, but I also find that I can stay out in the sun somewhat longer without that telltale "tingle" since my Vit D is rather higher than officially recommended. When I was in Australia a few years ago my first purchase was sun screen; I carried it with me, but never felt a need to use it. And never got a sunburn. I'm a great believer in the benefits of Vit D on sunburn prevention.