Babies & Heat Rash: What You Should Know

As a newborn parent, you have read all of the books and are ready for the task. Still, you might feel a little anxious about some unexpected surprises, like a heat rash. When there is a red bumpy rash, it is common to be a little concerned - all parents feel this way. New parents worry about their baby, especially when you don't understand the causes behind a few common ailments. 

Don't worry! Almost all babies will develop a heat rash during the first few months of their lives. Whether your baby is on the go or you live in a warm climate, they will sweat. However, unlike adults, these sweat glands are not fully developed. Babies tend to have a higher body temperature than adults, and they cannot regulate it like a grown person. Add into crawling and climbing, and that leads to a higher chance of developing heat rash. When you unwrap your baby and see a rash, try not to panic. These rashes are typical, and there are many ways to treat them. 

Do you want to receive a monthly subscription of amusing products for your baby? At 123 Baby Box, we have plenty of options to bring home a box of fun!

Related: Signs Your Baby is Overheating

What Is Heat Rash?

As you already know, heat rash is a common ailment in babies. Other names for heat rash is malaria or prickly heat. While it is common in babies, adults can develop heat rash. If you live in a hot, humid environment, your baby will likely develop this skin irritation. This rash happens when sweat ducts (or blocked pores) trap sweat under the skin. 

Most of the cases are minor with superficial blisters, but some babies can develop large red lumps. These rashes are often itchy. In many situations, your baby's heat rash will clear up on its own without medical intervention. However, you should always reach out to your pediatrician. With some helpful advice, you can help relieve your baby's symptoms to prevent sweating and cool down the skin. 

a parent holding the baby's hand

The Three Forms of Heat Rash

Heat rash is an all-encompassing name for red skin irritation, but there are three different types of heat rashes. 

Miliaria crystallina

This type of heat rash is one of the mildest forms. Only the top layer of the skin, known as the epidermis, is affected by this rash. Miliaria crystallina develops small, blister-like bumps on your newborn's skin. These bumps might look concerning, but they're not painful or itchy. If the bumps are scratched, they can break open. With this rash, you might want to put soft mittens on your baby's hands to prevent any accidental scratching. 

Miliaria rubra

A red, bumpy rash that affects the mid-epidermis is called miliaria rubra. Some people refer to this rash as "prickly heat." The red bumps are tender to the touch, with an itching or stinging sensation. This type of heat rash is the most common one. The irritations make many babies feel uncomfortable as the inflammation tries to heal. In some cases, miliaria rubra can develop bumps on the skin. 

Miliaria profunda

One type of heat rash affects the deepest layer of skin (the dermis). This rash is very rare among newborns and toddlers. As the sweat leaks out of the glands, fluid-filled pockets develop under the layer of skin. These bumps are not red or clear but are skin-colored. You might think that this heat rash is milder, but it can lead to more serious problems if not treated. 

Related: Why Does My Baby Cry So Much?

What are the Symptoms of Heat Rash?

Many babies will develop a rash on a body part that has been exposed to heat. Warm clothes, poor ventilation, and heavy swaddling can all increase the chances of heat rash. These rashes are more likely to appear in the baby's skin folds, particularly near the groin, armpits, inner thighs, or neck.

Some of the common symptoms include:

  • Pin-sized blisters
  • Red rash
  • Hot skin

The different types of heat rash can produce various symptoms. For example, miliaria crystallina will look similar to sweat, but the blisters are not inflamed or red. Miliaria rubra is itchy, developing tiny red blisters or bumps on the skin. Skin-colored blisters from miliaria profunda often look like pimples. Finally, miliaria pustulosa develops blisters that can break open and bleed. 

 a mother holding a baby

What Causes It?

When a sweat duct becomes clogged, a heat rash can develop. A clogged duct traps perspiration under the skin in many instances, causing inflammation. Babies don't have fully developed sweat ducts. These ducts can rupture more easily, trapping sweat under the skin. These rashes are common during the first weeks of life, especially if the baby has a fever or is dressed in warm clothes. Even blankets can cause the baby's skin to become too warm and develop a heat rash.

Potential Treatments

As soon as you cool the skin, the heat rash will clear up in many cases. You can cool the skin by removing extra layers of clothing. If you live in a hot environment, move the baby to a cooled indoor space. You should remove any damp clothing and diapers from the baby. For small patches of heat rash, you can even apply some water. Just dab a wet, cool cloth on the inflammation to bring down the skin temperature. You can treat larger areas with a cool bath for at least 10 minutes. Never use soap in the skin since that can lead to more irritation. You might want to use a calamine lotion or anhydrous lanolin creams for your baby - just check with your doctor before applying them.

Related: When to Stop Swaddling Your Baby


Heat rashes can look scary, but they are a common ailment for newborns and toddlers. With some precautions, you can prevent them from developing. If you are concerned about a rash on your child, it is always a good idea to check with your pediatrician. 

Are you looking for some monthly fun and surprises for your baby? At 123 Baby Box, our award-winning monthly subscription box is customized for your baby.

What to read next

123 Baby Box sources ideas for their blog content from a variety of channels including feedback from subscribers, trending topics in baby care, and insights from industry experts. They aim to cover topics that are both informative and relevant to the needs and interests of parents and caregivers.

The writing process at 123 Baby Box typically involves several steps. First, they outline key points to cover in the article based on thorough research.

123 Baby Box publishes new content on their blog on a weekly basis. This regular schedule helps keep their audience engaged and informed about the latest in baby care, product recommendations, and parenting tips.

The blog posts for 123 Baby Box are typically written by content writers who specialize in parenting, child development, and health. These writers often have backgrounds in journalism, education, or healthcare, providing them with the expertise necessary to produce reliable and valuable content for parents.

123 Baby Box writers put in a lot of time researching and fact checking each article.

123 Baby Box is a subscription service that provides monthly boxes filled with products tailored for babies and toddlers.

Baby Box Subscription

Monthly subscription box for babies aged 0-3 years - delivering unique, fun products

star star star star star
(5.0 rating)
take baby quiz