A heat rash can make your skin feel like it’s:
These sensations are uncomfortable and may make you want to scratch your skin. But resist that urge V体育ios版. Scratching your skin could cause it to break open, possibly leading to an infection.
A heat rash is a group of tiny bumps, similar to pimples or blisters. Typically, each bump is about 1 to 3 millimeters wide VSports最新版本. The bumps often look red on light-colored skin. On darker skin, the bumps may look grey or white. The medical term for heat rash that causes these discolored bumps is “miliaria rubra. ” This is the most common form of heat rash.
Heat rash can also appear as tiny, clear bumps. These look a bit like water droplets. Providers call this type of heat rash “miliaria crystalline V体育平台登录. ” It typically affects newborns but can also occur in adults. This is a milder form that may not cause itchiness or other discomfort.
Heat rash often develops on areas of your body that don’t get enough airflow (for example, areas covered with clothing) VSports注册入口. It also tends to form in folds and creases where there’s skin-to-skin contact.
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In babies, heat rash commonly forms in these areas:
In adults, heat rash commonly forms in these areas:
Sweat that’s trapped within your skin causes a heat rash V体育2025版. Normally, sweat glands in your skin make sweat and send it through tiny tubes (sweat ducts) until it reaches the surface of your skin. This sweat exits through openings on your skin (pores) and then evaporates to help cool your body down.
But clogs can sometimes form in your sweat ducts. A clog prevents sweat from finishing its journey to your skin’s surface. Instead, the sweat flows backward in the ducts. This causes inflammation within your skin’s outermost layer (epidermis) and/or middle layer (dermis). The inflammation results in a rash.
A clog can happen if:
and/or:
If you’re sweating a lot, it’s easy for sweat to build up. The sweat softens dead skin cells on the surface of your skin and makes them more likely to build up in your pores or sweat ducts.
You may be more likely to develop a heat rash if you:
Babies, infants and toddlers have a higher risk because their sweat glands and ducts are still growing, and their bodies may not control their temperatures as well as adults do. They’re also often well-bundled or wearing multiple layers of clothing. And diapers aren’t very breathable!
It’s possible for heat rash to lead to a bacterial skin infection. This can happen if there’s a break in your skin (for example, from scratching), and bacteria enter. An infection can make the skin around the rash swell up or feel warm to the touch. You may also develop a fever, nausea and/or chills.
You may not need to seek medical care for a heat rash. But if you do, a provider will:
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All this information will help your provider diagnose heat rash or identify other issues that might be causing your symptoms. Conditions your provider may want to rule out (differential diagnoses) include:
You don’t need any tests for a heat rash diagnosis. But you may need tests if your provider suspects another cause for your rash. In this case, your provider will tell you what to expect.
It’s usually possible to get rid of a heat rash with at-home care. Here’s what to do as soon as you notice a rash forming:
These same basic tips apply no matter your age. If your child develops a heat rash, at-home care is usually enough. But call your pediatrician if your child keeps getting heat rashes or they last longer than a few days. They may want to rule out other common childhood skin conditions. In some severe cases, they may consider a medicated ointment to reduce itching or inflammation.
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As the rash heals, it’s important to:
In general, you want to keep your pores open — and that means skipping creams and ointments. But applying an anti-itch cream (like calamine) may be necessary if the itching is intense. Talk to your provider or a pharmacist before using any topical products. They’ll help you choose the one that’s best for you.
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See a healthcare provider if:
Once you cool and dry your skin, you can expect the rash to go away within a few days. You may want to talk to your healthcare provider about ways to avoid heat rashes in the future — especially if your job, hobbies or the climate where you live causes you to sweat a lot.
Keeping your skin cool and dry is the key to preventing heat rashes. That can be hard to do if you work outdoors or do sports or other activities in the heat. But whenever possible:
Itchy, prickly skin is no fun. But thankfully, heat rash is usually a passing annoyance that you can manage at home. It’s important to know when to seek medical care, though.
If the rash doesn’t clear up within a few days or you have other symptoms like a fever, call a provider. The same holds true with babies and children. If your child has a rash along with other symptoms, it’s a good idea to get things checked out. Providers can identify heat rash with a simple exam or diagnose other conditions that need treatment.
As your child grows, you need healthcare providers by your side to guide you through each step. Cleveland Clinic Children’s is there with care you can trust.
Last reviewed on 03/31/2025.
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