Heat Rash: What You Need to Know

Now that summer is here, so are the inevitable bumps, bites, sunburns—and rashes. One of the most common warm-weather rashes I see parents ask about is heat rash (also called prickly heat or miliaria).

The good news? Heat rash is very common in children and is usually harmless. Although it can look alarming, it typically resolves on its own within a few days with some simple measures at home.

As an emergency physician—and a parent myself—I've put together a quick guide to help you recognize heat rash, treat it at home, and know when it might be time to seek medical attention.

What is heat rash?

Heat rash occurs when sweat becomes trapped under the skin. This most often happens during hot, humid weather or when children are overdressed or sweating heavily. Babies and young children are especially prone to heat rash because their sweat ducts are not yet fully developed.

What does heat rash look like?

Heat rash typically appears as:

• Tiny red, pink, or skin-colored bumps in clothed areas, like the t-shirt zone

• Tiny clear blisters (sometimes described as looking like beads of sweat)

• A mild itchy or "prickly" sensation (usually very mild if present at all)

It commonly appears in clothed areas where sweat and heat become trapped, including:

• The neck

• Chest and upper back (t-shirt zone)

• Armpits

• Groin and diaper area

• Skin folds

Unlike many infectious rashes, children with heat rash usually feel well otherwise and are not bothered by the rash.

How can I treat heat rash at home?

The treatment for heat rash is simple: cool your child down.

✓ Move your child to a cool, shaded, or air-conditioned environment

✓ Dress them in loose-fitting, lightweight clothing (cotton is ideal), avoid overdressing

✓ Give a lukewarm bath or shower

✓ Allow the skin to air dry when possible

One important tip: avoid thick creams, ointments, and heavy moisturizers, which can further block sweat glands and make the rash worse.

How long does heat rash last?

Most cases improve within a few hours to a few days once your child is kept cool and dry. Some more inflamed rashes may take a little longer to fully disappear.

When should I worry?

Heat rash itself is not dangerous, but it can sometimes be mistaken for other conditions.

Seek medical attention if:

• Your child develops a fever or appears unwell

• You are worried about dehydration (dry lips, sunken eyes, lethargic, not peeing as often as usual, etc)

• The rash is extremely itchy, painful, swollen, or drains pus

• The rash is rapidly worsening (spreading redness, worsening pain or itching, etc)

• Your child is unusually sleepy, irritable, or not drinking well

• The rash has not improved after several days of home treatment

The bottom line

Heat rash is one of those childhood conditions that often looks worse than it is. In most cases, it simply means your child's skin is telling you they're too hot. Cool them down, dress them lightly, and give their skin a chance to breathe.

And remember: if your parental instinct tells you that something doesn't seem right, it's always okay to seek medical advice.

This post is for educational purposes only and is not a substitute for medical advice from your healthcare provider.