Think Kevin Bacon. He stripped to gad about in the movie he played a brilliant scientist in. Developed some invisibility potion and lost his marbles from the power it gave him. But he strolled about nekkid for a while, and that had to have some effect. Negate the effect of the cold by saying you were living in a warm enough climate, and if you were invisible it might not matter about the cloak of darkness. So, you take the potion, become unseeable, go jaybird and strut the streets. The sun is still shining and it’s gotta go somewhere.
So if your invisibility is based on refraction, that is the light hits you and the potion has made it so it just bends around you and kinda goes right through you no matter what angle it comes from and just shows whats behind you it still hit you. And if it’s reflection it hit you the same. In fact the only way the light didn’t hit you is if you weren’t there and if you weren’t there there never would have been a book or movie or sequel ar remake.
So if it hit you can you get sunburnt? There you are, strutting about in your altogether and yes, there are some areas on your body that have seldom seen the light of day. Those areas are sensitive, way sensitive to sunburn, just ask someone with the experience. So invisible or not, the sun hits you in those delicate areas with all its gamma and ultraviolet and beta rays and such, might it not have some effect? That’s gotta hurt. And it might even have long term undesirable effects like blotch and scrofula and such. Could the invisible woman wear sunscreen, like some clear, less oily Coppertone and still be invisible or would he leave a woman shaped mirage for anyone to see? We all knows what happens when she eats or drinks and it’s disgusting. Those irregular globs, chunks and morsels moving by peristalsis down her epiglottis until the transparency of her self takes over and blocks them from further view.
Now this question occurred to writer not because his residence is in Washington state, nor because he’s visiting Colorado, but merely because the untrammeled mind is free to wander and wander it did. What you think, is sunburn even an issue to the invisible man or is there some underlying factor that renders it moot. (Moot used to mean germane, lookit up.)