"Summer heat stimulates the oil glands to produce more oil, plus sweat can cause dead surface skin cells to swell and clog pores," says Lupo. As a result, even women blessed with clear skin the rest of the year may struggle with breakouts in the summer—not only on the face but also the back, chest, and even butt. To keep those bumps at bay, dermatologists recommend salicylic acid. "It's lipophilic—attracted to the oily areas that are more likely to break out," says Lupo. "It's also an exfoliator, so it keeps your pores clean." Switch to salicylic acid cleansers (try SkinCeuticals Clarifying Cleanser for the face and Neutrogena Body Clear Body Wash for the body), but resist the temptation to overwash. Morning and evening is plenty. (Lupo sanctions one extra, postworkout wash—but use a milder cleanser.) Skip moisturizer, and use just a noncomedogenic sunscreen that contains zinc oxide or titanium dioxide (they provide a more matte finish). At night a layer of benzoyl peroxide (try Proactiv Advanced Blemish Treatment) on problem areas will also help reduce breakout-causing bacteria.