Bothered by Red, Itchy Skin on Hot Days? Doctors Share How To Get Rid of a Heat Rash Quickly

We love the laid-back, carefree days of summer. But just like winter months lead to dry, flaky skin, the sunny season comes with its own skin saboteurs. One worth paying attention to: heat rash. Here’s what you need to know about heat rash, including what it looks like, why it happens and how to get rid of a heat rash quickly.

What is a heat rash?

When the skin is subject to excessive heat and sweating, the sweat pores can become blocked, explains Brynna Connor, MD, a board-certified family medicine physician in Austin, TX, and healthcare ambassador at online pharmacy NorthWestPharmacy.com. That’s problem on hot summer days.

“Heat rash happens when there is excess heat [trapped] in the body,” says Aya Ahram, DO, a board-certified dermatologist at Hudson Dermatology & Laser Surgery in New York, NY. Essentially, when your core body temperature increases, you produce more sweat. But if your sweat glands are clogged (more on that below) a heat rash can appear. The condition affects up to 30% of adults in humid climates.

How sweat glands get clogged

If you wear a heavy moisturizer or lotion, it can easily block sweat glands if you start overheating, says Dr. Connor. Your clothing choices may also cause trouble if the fabric (such as polyester) can’t wick away moisture. This causes sweat to sit on the skin and build up, blocking pores.

Casts, bandages and anything else that’s bound tightly to the skin increase the risk of heat rash when exposed to warmer temperatures, too, adds Dr. Ahram.

Why women are prone to heat rash

“Hormonal changes can impact heat rash in women,” says Dr. Connor. “Having hot flashes in perimenopause and menopause may cause them to sweat more, which increases the risk of heat rash.” Avid exercisers or those who live in warmer climates may be more prone to heat rash, particularly as their hormones change.

Even if you’re not in menopause, your menstrual cycle may increase your risk of a heat rash, says Dr. Ahram. “If you’re on your cycle and not feeling well, you may be lying down for longer periods of time,” she says. “If you’re sweating from a hormonal shift, and that sweat is sitting on your back, it’s causing occlusion. This will block sweat glands and could lead to a heat rash.”

What heat rash feels like

Some people may mistake a heat rash for an allergic reaction, says Dr. Connor. But if you haven’t changed any of products you’re using, then the issue may be an increase of your core body temperature. Signs of heat rash include:

• Red, itchy skin
• Blisters that can be painful
• Tiny, red bumps

Heat rash can appear anywhere, but it’s common on the arms, legs, back, underarms and groin (think: areas you sweat a lot). If you wear tight clothing, like a bra strap that’s snug, you may see a heat rash there since the skin is not able to breathe.

How to get rid of a heat rash quickly

Heat rash will go away on its own in one to two weeks, says Dr. Ahram. Still, there are some tricks that can help speed along the process and get rid of a heat rash quickly:

1. Use hydrocortisone

If your heat rash is especially itchy, an over-the-counter low-dose steroid (like Cortizone 10 Maximum Strength Anti-Itch Ointment) can help get rid of symptoms quickly. “If you keep scratching an itchy heat rash, it’s possible to get a secondary bacterial infection,” says Dr. Connor. “This can lead to bigger skin problems and a need for an antibiotic.”

Tip: “Avoid using an OTC hydrocortisone on areas like the face or anywhere there’s skin-on-skin [contact] like the armpits or groin area,” adds Dr. Ahram. These areas are more sensitive and can become irritated easily.

2. Chill your calamine lotion

Calamine lotion is another medicine cabinet staple that helps get rid of heat rash symptoms quickly. The zinc oxide in it calms irritated skin. And you can boost the benefit by knowing where to stash it. “Keeping your calamine lotion in the refrigerator can provide extra relief to skin with heat rash,” says Dr. Ahram. This can help reduce inflammation, swelling and itching.

3. Use lightweight lotion

For minor skin abrasions, many of use reach for Vaseline. But Dr. Ahram says to skip this ointment on a heat rash because it creates a physical barrier that clogs sweat ducts. Instead, Dr. Connor says to choose a lightweight, fragrance-free lotion for sensitive skin like Aveeno Calm + Restore Oat Repairing Lotion, CeraVe Itch Relief Moisturizing Lotion or Cetaphil Moisturizing Lotion.

If you want to skip lotion all together, Dr. Connor says aloe vera can provide relief from heat rash. Just make sure to use one that is alcohol-free, like Fruit of the Earth Aloe Vera 100% Gel. (Discover more health and beauty benefits of aloe.)

4. Swap your bar soap

“If you’re prone to heat rashes, stay away from bar soap,” says Dr. Connor of the more traditional, harsh bar soaps. “This type of soap will dry the skin out, and the body will react by creating more oil. This leads to a combination of oil, sweat and moisture on top of the histamine release from the body that causes redness and itching. It’s the perfect storm for heat rash to continue.”

Instead, use a moisturizing cleanser like Cetaphil Gentle Skin Cleanser. If your heat rash is particularly uncomfortable, apply the cleanser gently with your hands rather than a more abrasive loofah.

Also smart: Turn down the water temperature while sudsing up. Cool showers keep your core body temperature low and prevent the skin from sweating even more. A cool bath can also help. Dr. Connor says soaking in a bath with 1 to 2 cups of colloidal oatmeal or Epsom salt reduces itching and inflammation.

If you can’t handle a cool shower or bath, using a cold compress can have the same effect. “Make sure there is a layer of cloth between the skin and the ice,” says Dr. Connor. “You never want to put ice directly on the skin — this can cause a burn.”

5. Wear cotton clothes

Both Dr. Connor and Dr. Ahram say cotton is the best fabric choice if you’re dealing with a heat rash because it wicks away moisture. “Choose loose-fitting clothing to let the skin breathe as much as possible, especially if you’re sweating or in a warm climate,” says Dr. Ahram.

6. Try an OTC allergy medication

“If you have a really itchy heat rash, or one that is causing a significant histamine release that leads to more redness and itching, antihistamine allergy medications like Zyrtec (cetirizine), Claritin (loratadine) or Allegra (fexofenadine) may help,” says Dr. Connor. Just make sure you check the label before you take one. Some antihistamines, like Benadryl (diphenhydramine) can make you drowsy.

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For more ways to treat (and prevent) skin summer conditions:

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A Top Sunburn Self-Care Remedy May Already Be in Your Fridge — Plus See What Doctors Say To Skip

How to Spot Skin Cancer on the Scalp (Hint: Your Hair Stylist Can Help) + 4 Ways To Cut Your Risk

This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.