BBC has an excellent guide on sun protection. It appears that too much time outside during daytime (even when cloudy or wearing sun protection) is slowly killing you. It is ironic that the Sun giveth and Sun taketh away at the same time. So, in a way, all humans are very much vampires that would do much better if they spent time outside only at night, so our ancient crepuscular ancestors had much better instincts than we do. Of course, I am glib making that remark, as our ancestor diminutive mammals had to be crepuscular by necessity of evading the apex daytime and nighttime predators of their days.