I have sensitive skin that turns red easily in the sun, especially at the locations where I have scars from acne and other injuries. With my atrophic scars, we

I have sensitive skin that turns red easily in the sun, especially at the locations where I have scars from acne and other injuries. With my atrophic scars, we know that UV can reduce collagen levels which would reduce the healing potential at those sites. For these reasons, I avoid UV exposure to my face as much as possible. For fair-skinned people like me, I would recommend generously applying sunscreen to face and hands and leaving the other areas uncovered if you are out in the sun for less than an hour or so with moderate UV index, or less than 20 minutes or so with high UV index. Longer than that, consider applying sunscreen to the rest of your body as well. Of course, ymmv.