Understanding Heat Rash (Prickly Heat): Symptoms and Relief

Written by Evan Starkman, Deanna Altomara
Medically Reviewed by Poonam Sachdev, MD on October 18, 2026

A heat rash is a common rash that can show up on your skin when you're hot or if you sweat a lot. It can make parts of your skin sting or feel prickly due to overheating. It can itch a lot, but it's not dangerous.

Some people call a heat rash "prickly heat" or "sweat rash." Your doctor might call it "miliaria."

Anyone can get a heat rash, but it's more common in babies and young children.

 

There are three types of heat rash.

Miliaria crystallina

It is the mildest type and happens when sweat ducts (pores) on your skin's surface get clogged. It usually looks like clear, fluid-filled bumps. The bumps can break easily.

Miliaria rubra

Often called prickly heat, this type can cause an itchy or prickly feeling along with small, inflamed bumps on your skin. If the bumps become filled with pus, your doctor will call it miliaria pustulosa.

Miliaria profunda

This type affects the skin's deepest layer. The bumps in miliaria profunda look like goosebumps and are firm and painful or itchy. They may break open.

Heat rash happens when the ducts beneath your skin that carry your sweat get clogged. The sweat can't get through the pores in your skin, causing irritation. Then, a rash develops.

This is most often caused by:

  • Small pieces of dead skin cells getting trapped in your pores
  • Sweat collecting between your skin and your clothing
  • Hair follicles blocking your sweat glands
  • Hormonal changes, like having your period
  • Not enough airflow between your skin and clothing 

Can a heat rash spread?

Yes, it's possible for a heat rash to spread to other parts of your body. It happens due to clogged sweat pathways.

Rashes are more likely to spread on parts of your body where your clothes are tight against your skin. That's especially true if you sweat.

Heat rash looks like tiny raised bumps surrounded by red, irritated skin. On darker skin tones, the redness may be less noticeable, or it may look darker.

Heat rash usually happens on your:

  • Neck 
  • Scalp
  • Chest
  • Groin
  • Elbow creases

Heat rash on face

Babies sometimes may get heat rashes on their face, but it's rarer in adults. When an adult gets a facial rash, it might be because of trapped heat and sweat from face masks.

To avoid this, try to gently clean your face after wearing a mask.

Heat rash under breasts 

Heat rashes tend to form in areas where skin rubs together, such as underneath your breasts. This can lead to a sore rash called intertrigo. It tends to affect people who have large breasts.

To avoid this, try patting the area dry with a clean towel. You can also apply zinc oxide paste or powder to your skin folds and wear a well-fitting, cotton bra.

Some things can make you more likely to get a heat rash. 

 

There's no standard treatment to get rid of a heat rash. It usually gets better once your skin cools off.

You can do some things at home to get relief:

  • Cool your body in an air-conditioned room or with a fan.
  • Take a cool shower or bath and let your skin air-dry.
  • Wear fewer layers of clothing.
  • Wear loose clothing that allows airflow.
  • Choose breathable cotton fabrics.
  • Don't scratch your skin to avoid infection.
  • Keep your skin dry.
  • Try an anti-itch cream like calamine lotion.
  • Take medication to lower a fever if that's causing your heat rash.
  • Try to shift your position and change your clothes often if you are on bed rest.

Call your doctor if you develop an infection where the bumps have burst, as you may need medication. Also call the doctor if you have a fever or any other signs of illness.

How to get rid of heat rash quickly

Heat rash tends to go away on its own in two to three days. Some home remedies, such as the ones described above, can help speed up the process. But there isn't a single quick fix for heat rash.

In the meantime, the first step is to cool down. This won't make the heat rash go away, but it can immediately help with the itchiness.

What's the best cream for heat rash?

Some creams can help with heat rash. They're not made specifically for heat rash but help with general skin irritation and itching. These creams are available over the counter, so you don't need a prescription.

The best creams for heat rash are calamine lotion and corticosteroid cream. One common type of corticosteroid cream is 1% hydrocortisone cream (this is different from hydrocortisone ointment, which can clog sweat glands). Talk to a doctor before using hydrocortisone cream for children younger than 10 or if you are pregnant.

Heat rash in young children can look uncomfortable, but it's usually not serious.

To treat your baby's symptoms:

  • Give them a cool bath and pat them dry gently.
  • Put them in an air-conditioned room, or position a fan so that a gentle breeze blows over them.
  • Avoid creams or ointments that may irritate the skin.

Call your pediatrician if:

  • The heat rash is still visible after three or four days.
  • The rash gets worse.
  • The rash causes serious itching.
  • The rash oozes pus or swells.
  • The rash is red or purple or looks like bruises.
  • The rash is tender.
  • Your baby has a fever.

You can't always prevent heat rash, but there are things you can do to significantly lower your risk.

 

Call your doctor about a heat rash if:

  • The rash is severe or painful or does not go away on its own within a few days.
  • You get an infection in an area where you recently had heat rash.
  • You have a fever or any other signs of illness.
  • The rash is bright red or has streaks.
  • The rash starts after you have been taking an antibiotic or a new medication.
  • The rash leaks pus or forms scabs.

Heat rash is pretty common. It happens when the ducts beneath your skin that transport your sweat get clogged. Most heat rashes usually get better on their own without any complications. If you have darker skin, you might notice lighter or darker spots that last a few weeks to months (called postinflammatory hypopigmentation or hyperpigmentation).

Here are some of the most commonly asked questions about heat rash.

Is heat rash contagious?

Heat rash isn't contagious, so you don't have to worry about spreading it to other people.

Can heat rash become infected?

Yes. Sometimes, heat rashes can get infected. Look for signs such as fever, swelling, or pus leaking from the rash. If this happens, your doctor may prescribe antibiotics.

What should I avoid putting on a heat rash?

Avoid tight clothing and heavy, oily moisturizers that can clog pores.

How long does heat rash usually last?

Heat rash usually lasts about two to three days. Call your doctor if it doesn't go away after three or four days (or if it seems to be getting worse).

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