When you’re exercising outside in the heat of midsummer, skin troubles like blisters and chafed thighs can be more than just a small annoyance.

They can interfere with summer exercise and can sometimes be enough to discourage you from working up a sweat, says sports dermatologist Brian Adams, M.D., M.P.H., chair of the University of Cincinnati Department of Dermatology and official dermatologist for the Women’s Tennis Association.

But there’s no need to let these skin problems sideline you. Here’s how to prevent them—or stay active in spite of them.

Chafing

When your skin rubs on skin—or rubs against rough or wet clothing—friction and moisture can leave it irritated, inflamed, and raw, Adams explains.

“Chafing may not look like much, but even mild cases can be irritating enough to cause pain with every stride when you try to walk or run or take part in any athletic activity,” he says.

How to prevent: Protect delicate inner-thigh skin from damage with a thin layer of petroleum jelly (or use one of the many anti-chafing products available over the counter) on areas of skin that rub together.

Invest in exercise shorts (like bike shorts) or leggings with a snug fit and no inner-thigh seams. Avoid cotton (it holds onto sweat) and rough fabrics; instead, choose performance materials like polyesters that can wick away moisture. 

“The fit should be tight, so there’s no friction with your skin,” Adams says. If you feel self-conscious in form-fitting shorts, you can wear loose workout shorts over them. And make sure your exercise clothes are clean and dry—sweat and dirt trapped in fabric can also be irritating.

How to treat: Clean already-irritated skin by leaving a warm, damp washcloth over the area for 5 minutes. Then pat dry and apply petroleum jelly. Repeat two to three times a day, Adams says.

You can also use an over-the-counter hydrocortisone ointment for a few days to reduce redness, swelling, and pain.  

Blisters

These fluid-filled bumps of skin “can literally stop people in their tracks, even professional athletes,” says podiatrist Karen A. Langone, D.P.M., of Southampton, N.Y., a past president of the American Academy of Podiatric Sports Medicine. “They can be incredibly painful.”

And if not treated properly, they can lead to infections.

How to prevent: Start with moisture-wicking athletic socks (avoid cotton), ideally socks that are seamless to avoid rubbing, Langone says. And make sure your sneakers or walking shoes don’t squeeze your feet or create friction. “When you buy them, there should be a thumb’s width of space between your big toe and the front of the shoe,” she says.

If you have a bunion or other areas that tend to rub against the inside of your shoes, apply a blister-prevention balm to your skin that will let your sock move over the area without irritating it. Alternatively, “a fabric bandage or paper athletic tape may work,” says Langone, as long as it’s not rolling or tearing when you move. “Experiment to find what’s best for you.”

How to treat: Got a blister? Cover it with a padded blister bandage so that you can stay active. If it pops, don’t peel off the top layer of skin—that will just expose the very sensitive skin underneath.  

Athlete's Foot

Tinea pedis, the fungus that makes skin between your toes and on the bottom of your feet flake, crack, and itch, thrives on sweaty summertime feet and is helped along by the moist conditions inside of sweat-soaked sneakers.

Left untreated, it can create a breeding ground for secondary infections.

How to prevent: Carefully wash your feet, including between your toes, every day, and dry thoroughly. Take your shoes and socks off when you can, to help keep feet dry.

Invest in a second pair of walking or running shoes and alternate, giving one pair a day off to dry out before you wear them again. “Don’t just throw your shoes back in your gym bag. Take out the liner and air everything out,” Langone says. 

In locker rooms, public pools, and public showers, wear flip flops or shower shoes. And wash your dirty socks with hot water.

How to treat: Wash and dry your feet every day. Some experts even recommend using a hair dryer to get rid of moisture in the gaps between your toes.

Try using an over-the-counter antifungal cream, spray, or powder containing active ingredients such as clotrimazole (Lotrimin and generic) as directed—usually for one to two weeks. If you don’t see any improvement, see a dermatologist, who can help diagnose the infection and prescribe something stronger if needed.

Drippy Sunscreen

You should always wear sunscreen when exercising outside. But sunscreen plus sweat can add up to a goopy, greasy mess, sometimes burning your eyes when it drips off your forehead.

How to prevent: Choose a water-resistant sunscreen for your arms, legs, neck, shoulders, and any other exposed skin on your body. All of the sunscreens tested by Consumer Reports are water-resistant; Equate Sport Lotion SPF 50 from Walmart, $5, is one of our top picks. For your face, you can also try a sunscreen stick—Up & Up Kids Sunscreen Stick SPF 55 from Target, $7, is our highest rated.

Add sunglasses and a broad-brimmed hat, especially between 10 a.m. and 4 p.m., when the sun is strongest. And reapply sunscreen every 2 hours, more often if you’re sweating or in the water.

How to treat: If you do get sunburned, soothe inflamed skin with a cool shower, apply a gentle moisturizer or aloe vera, and stay hydrated to help your body cool off. Don’t peel the burn or pop any blisters.

Stay out of the sun to avoid more damage. If you have to be outside when it's sunny, wear clothing that covers burned spots.