I leave an air-conditioned oasis and in a matter of minutes, I'm slick with sweat.

First, if you've been using a deodorant, try an antiperspirant. Most contain aluminum compounds that occlude sweat ducts and prevent perspiration from reaching the skin's surface (where it's exposed to bacteria that make it smell…not so fresh). Drugstore brand Certain Dri contains a higher percentage of aluminum chloride than most other over-the-counter antiperspirants; apply it at night, and in a few days you should notice significantly less sweating. (No studies have confirmed the rumors that aluminum is linked to Alzheimer's or breast cancer.) Your doctor can prescribe the stronger Xerac AC or Drysol. Whatever the level of protection, it will be more effective on bone-dry skin, says Loretta Ciraldo, MD, clinical professor of dermatology at the University of Miami Miller School of Medicine, who tells patients to dry their armpits with a hair dryer (on the cool setting) before applying antiperspirant.

As for the rest of your body, if you find your clothes sticking to you on steamy days, skip the body lotion and instead apply a dusting of powder, like Dr. Hauschka Body Powder, before you get dressed. For serious sweaters, Ciraldo recommends a more heavy-duty powder, called Zeasorb-AF; it's an antifungal as well, so it guards against rashes that can break out on warm, damp skin. On our feet (and in our shoes), we've been sprinkling Feet by OPI Powder Protection to avoid slipping and sliding; Summer Soles, thin fabric shoe liners, help as well. Applying antiperspirant to the bottoms of your feet before bed will also curb sweat, says Mary Lupo, MD, clinical professor of dermatology at Tulane University School of Medicine. She even tells (dedicated) patients to wrap Saran Wrap over them afterward to improve absorption.

I'm breaking out—everywhere.

"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.

Every sunscreen I've tried looks like a greasy white mask.

Zinc oxide and titanium dioxide are great broad-spectrum sunblocks, but they can look a little chalky—and the higher the SPF, the more likely you'll resemble a Marcel Marceau impersonator. There's no need to go above SPF 30, says Ciraldo, who also recommends choosing a tinted formulation (we like Murad Oil-Free Sunblock SPF 15 Sheer Tint). Or you can look for sunscreens that contain Parsol 1789 (often listed as avobenzone), which might feel a little greasier than the mineral blockers but won't have a whitish cast.

The bottle of self-tanner said "subtle glow," but what I got is a streaky mess.

Next time: Exfoliate, exfoliate, exfoliate before you even get near self-tanner, and make sure your skin is completely dry. Tinted formulations, like Lancôme Flash Bronzer Glow 'n Wear, are easier to apply because you can see the spots you missed. We can't say enough great things about slow-build self-tanners (like our new golden girl, Victoria's Secret Bare Bronze Daily Glow Moisturizer). They really are subtle (it'll take a few days to get a truly tanned look). If you've gone overboard with a self-tanner, all you can do is scrub off the streaks, says makeup artist Julie Hewett. For more concentrated stains around the ankles or wrists, she recommends cuticle remover.

I just had a manicure yesterday, and the polish is already turning yellowish.

The sun's alchemic powers aren't limited to your hair and skin. "It takes only a day or two for the sun to discolor or fade nail polish," says manicurist Deborah Lippmann. "Always look for a topcoat that contains a UV inhibitor. They often say 'non-yellowing' on the bottle." (We like Lippmann's On a Clear Day and Nailene Sun Shield.) Outdoor action can also wear away polish more quickly than usual (strolls on the sand are brutal on pedicures), so be sure to apply very thin coats of color, which are less susceptible to chipping than thick ones.