Stay Cool and Rash Free: 6 Tips for Treating Heat Rash

As warm, sunny weather approaches, it’s time to learn about a pesky summer visitor called heat rash. This unwelcome rash causes redness, irritation, and discomfort. 

While there’s no quick fix for heat rash, there are treatments that can soothe your skin. And if you’re more prone to heat rash, there are steps you can take to keep your skin smooth and rash free all summer long.

What is heat rash?

Heat rash — or miliaria rubra — is a skin rash that can develop when sweat glands on the skin get blocked. It also goes by the names prickly heat and sweat rash.

Sweat glands get blocked all the time. But when you sweat too much too fast, the salt in your sweat can block the sweat glands even more. So, anytime you sweat, you can develop heat rash. Once you have heat rash, any ongoing sweating can make the rash worse, creating a vicious cycle.

People commonly develop heat rash after being exposed to hot or humid weather. Interestingly, you’re more likely to develop heat rash when you first get to a hot climate. After a while, your body adjusts and you sweat less. This makes you less likely to develop heat rash. This is good news if you’ve just moved somewhere warm. But it’s not great news if you’re only somewhere for a short time, like on vacation. 

Other things that increase your risk of heat rash include:

• Exercise or any physical activity that makes you sweat

• Wearing tight clothing

• Wearing a medical dressing or medication patches 

• Illnesses that cause fever

• Taking medications that cause sweating like bethanechol, clonidine, and neostigmine

Heat rash isn’t contagious. It’s also not dangerous and doesn’t cause skin scarring. 

In rare cases, people who get severe back-to-back episodes of heat rash can develop damage to their sweat glands. Damaged sweat glands may make too much sweat, which can lead to excessive sweating. Or they may stop making sweat, which can put people at risk for heat exhaustion or heat stroke.

What does heat rash look like?

Heat rash looks like small, raised bumps. They may be red and slightly itchy. The itchiness usually gets worse when you sweat.

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You can develop heat rash anywhere on your body. But it’s most likely to appear on parts of your body that rub against clothing or in your skin creases. People most commonly notice heat rash on their:

• Back

• Chest

• Neck

• Armpits

• Groin

What gets rid of heat rash?

The bad news is that there’s no way to get rid of heat rash fast. The good news is that it will go away on its own in about 2 to 4 days.

But some things speed up the process by breaking the sweat-rash cycle. These at-home treatments can also keep you from developing heat rash again.

1. Cool off

Move to a cooler environment as soon as you can. This can be in the shade or under a tree or umbrella. Better yet, move somewhere indoors with air conditioning. You may not be able to escape the heat forever, but take breaks whenever possible.

Fabrics can trap a lot of heat against your skin. Try wearing loose clothing and opt for breathable fabrics like cotton. Make sure you’re using lightweight bedding, too. 

If you’re wearing a medical dressing or compress, talk to your healthcare provider about whether you can loosen or remove it for part of the day. Your provider may have recommendations about options that are more breathable and less likely to trap heat. 

2. Take a cool bath or shower

A cool bath or shower does double duty. It helps your body cool off. And it soothes irritation from heat rash. 

If you only have a small area of heat rash, you can try applying a cool compress to the area for 10 to 15 minutes. Just run a small towel or cloth under cool water and then apply it to your skin.

Keep in mind that water should be cool, not freezing. Very cold water or ice packs can lead to cold injury, which can damage your skin.

3. Exfoliate

While you’re enjoying that cool bath or shower, gently exfoliate your skin using a cloth or mild loofah. Exfoliating gets rid of dead skin cells, dried sweat, and other things that could be blocking your sweat glands. Opening up those sweat glands keeps your heat rash from getting worse and taking longer to heal

4. Take an antihistamine

Heat rash can be itchy, but avoid the urge to scratch. Scratching irritated and damaged skin can lead to skin infections. 

You can try taking an over-the-counter (OTC) antihistamine to combat that itchy feeling, such as:

• Diphenhydramine (Benadryl)

• Cetirizine (Zyrtec)

• Loratadine (Claritin)

• Fexofenadine (Allegra) 

Benadryl can make you feel sleepy so it’s best used at night, especially if itchiness is keeping you awake.

5. Try a gentle soap and lotion

Soap can actually worsen heat rash by irritating skin and drying it out. Until your heat rash heals, opt for a gentle soap that’s fragrance and dye free. You can also use a gentle moisturizer to soothe your skin. But make sure it’s also fragrance and dye free. For added relief, keep your moisturizer in the refrigerator so it can cool off your skin.

6. Prescription medications

If you have heat rash all over your body or your heat rash is very bothersome, it’s time to talk to your healthcare provider. There are prescription medications that can help treat heat rash. 

Topical steroids can help you recover faster and reduce itching. Most people need higher-strength steroids than the kind that are available OTC. 

Antibiotic ointments are another option that can bring down inflammation by stopping bacteria from growing within blocked sweat glands. Popular options include clindamycin and erythromycin ointments. 

Why trust our experts?

Written by:

Ronald W. Dworkin, MD, PhD

Ronald W. Dworkin, MD, is a board-certified anesthesiologist who has been practicing anesthesiology in a community hospital for 30 years. He has taught in the honors program at George Washington University for over 10 years and works as a senior fellow at the Hudson Institute.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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