Check out some of the people interested in quantum biology on youtube. They are talking about ways to use the sun to create a "solar callus" so that you don't burn. They do say use the shade & hats etc as well but they dont use sunscreen and many are based in Australia where the "slip, flap, slop"
T shirt, hat & sunscreen is national folk law.
( They are also talking about the new science which shows that sunlight powers our mitochondria and artificial blue light is really damaging to us. We are designed to live in sunlight not inside buildings. Sounds bizarre and not main stream but strong science behind it)