man, becuase I have olive skin, in the winter I turn kindof yellow. So I go tanning a couple of times in the cold months and I've gotten burned so badly in those things. My gawd. Once on the ass is enough. Ur not supposed to wear spf in there, but I do now. I burnt my face really badly in a stand up one once too. ouch. Then I had to work and everyone was like, grimmacing at me. It hurt.