How to keep ‘chub rub’ from chafing your skin and ruining your summer

You deserve to enjoy the warm weather.

Summer’s right around the corner, but the heat is already on. From unrelenting sunshine to sizzling grills, feeling hot (and cooling down) are part of the daily grind now. PopSci is here to help you ease into the most scorching season with the latest science, gear, and smart DIY ideas. Welcome to Hot Month.

The weather is finally getting warmer, and you know what that means: It’s chub rub season. Whether you experience chafing after vigorous outdoor jogs or whenever you leave the house, it’s important to know to soothe your sore skin—and keep this painful friction from afflicting you in the first place. 

What causes skin chafing? 

First, a little primer on the physiology behind the dreaded chub rub. “Chafing is a pretty common skin issue,” says Lacey Kruse, a dermatologist at Lurie Children’s Hospital and an assistant professor of pediatrics-dermatology at Northwestern University School of Medicine. “It’s essentially caused by there being too much friction for the skin to handle.”

Your skin can chafe under the assault of any kind of friction—be it from clothes or another patch of skin—but certain conditions make that close contact more dangerous. 

“Skin cells are more fragile when wet, so any kind of moisture means the skin loses some of its structural integrity,” Kruse says. “In the summer, when you’re maybe spending time at the pool or the beach, or simply sweating more, that makes your skin more sensitive to friction.”

That means sweaty skin is more likely to develop micro-tears that can develop into tender spots, blisters, and even erosions. 

Skin chafing is especially common on the inner thighs and buttocks, where friction is likely to occur when you walk or run. But Leah Spring, a dermatologist in Virginia Beach, Virginia, notes that it can strike other parts of the body as well. In addition to the thighs, she says, skin underneath the bra band is at risk for chafing, as are parts of the feet. “The nipples, head of the penis, and scrotum can also be victims to chafing, particularly in runners, surfers, or anyone exercising vigorously on a sandy beach,” she says—grains of sand provide yet another opportunity for harsh friction against your fragile skin. 

How can I prevent skin chafing?

Preventing chub rub comes down to minimizing the friction on your skin. There are a few ways to accomplish this. 

First, consider your clothing. While skin-on-skin contact can easily and obviously lead to chafing, both Kruse and Spring note that too-loose fabric can hurt you, too. That cool, breezy feeling won’t last long as excess cloth rubs against your skin. Well-fitting clothing that stays in place as you move will absorb the friction that would otherwise go right to your skin cells. A tight-fitting baselayer can do the trick while you’re running or cycling. If you experience inner thigh chafing while doing everyday activities, try fitted bike shorts or slip-on bands designed to cover areas that would otherwise rub together

Another way to reduce friction is to lubricate your skin. Products like Body Glide, Monistat’s Chafing Relief Powder Gel, and Megababe make your skin slightly slippery to avoid irritation. Try applying one of these products on clean, dry skin before you get dressed. You can reapply throughout the day as needed. 

[Related: How to leave the sand behind on your next beach trip]

Another important thing is to stay dry. Consider wearing moisture-wicking fabrics, applying a body powder while getting dressed, or simply changing out of damp clothes (and toweling off) as needed. 

This is where a commonly-cited life hack comes in: antiperspirant. Some folks swear by using the stuff in place of products like Body Glide. Kruse notes that using a deodorant stick on your inner thighs or another commonly affected area won’t actually provide much lubrication, but an antiperspirant could reduce the risk of chafing by minimizing sweat. “It wouldn’t prevent the chafing itself,” Kruse says. “But if you’re prone to sweating, it might make a difference.” Spring suggests swiping an antiperspirant onto your bra band area or onto the bottoms of your feet the night before you plan to engage in outdoor activities. You can even invest in some antiperspirant wipes for on-the-go sweat mitigation. 

What should I do to treat chafed skin?

You did your best to prevent it, but you’ve still come home from a summer outing with red, inflamed skin. Don’t panic.

“Most chafing can be treated at home with rest, time, and gentle skin care,” Spring says. Start by gently washing—not scrubbing—the affected area with a mild soap and patting it dry. You should then apply a greasy ointment like Vaseline or Aquaphor. Thick ointments help keep your skin moisturized and protected as new cells grow, and you should keep the angry area greased up with twice-daily applications until it heals completely. If you’re in a lot of discomfort, try soothing the irritation with aloe or a cold compress. Try to minimize friction to the area while it heals, which should take a few days. 

If you start to develop pustules, painful red bumps, intense swelling, or bleeding, it’s time to go see a doctor. While it’s likely your chafing will clear up with the help of a topical anti-inflammatory, broken skin always carries a risk of infection—so in really severe cases, you might need antibiotics. 

There’s no magical cure for ridding yourself of chub rub overnight. But, as is so often the case, an ounce of prevention is worth a pound of cure—so lube up your thighs, slip into some bike shorts, and enjoy the warm weather without letting friction get the best of you. 

Rachel Feltman

Rachel Feltmanis the Executive Editor of Popular Science and the host of the podcast The Weirdest Thing I Learned This Week. She's an alum of Simon's Rock and NYU's Science, Health, and Environmental Reporting program. Rachel previously worked at Quartz and The Washington Post. Contact the author here.