Heat Rash is Not Just for Infants

Community Member

In most parts of the country, this has been a sweltering summer with tons of heat and humidity. Many questions have come in to My Skin Care Connection about skin problems related to sun exposure including bad sunburns and even sun poisoning. But in addition to the dangers of the ultraviolet rays of the sun, there can also be ill effects to our health and skin from the summer heat. Most of us know that babies can develop heat rash   but adults can get it too. Some of you have been writing in to ask about developing a rash after you have been out in the sun, heat, and humidity. One possibility may be a heat rash, but always do consult with your doctor or dermatologist if you have an unexplained rash which does not go away.

What is heat rash?

Heat rash or prickly heat is a rash caused by excessive sweating especially during hot and humid weather. If the sweat glands become blocked then perspiration may get trapped under the skin and result in skin irritation of small red bumps or blisters.

What are the symptoms of heat rash?

  • Clusters of small blisters or red bumps. You may have a few scattered here or there or hundreds.

  • Sometimes the rash may itch or feel prickly.

  • Heat rash usually develops in skin folds or where your clothing can cause friction. Likely areas for heat rash to occur include the neck, upper chest, groin, under the breasts, armpits, and elbow creases.

  • To see what this rash may look like the online version of The Merck Manual of Medical Information-Second Home Edition has an image of heat rash.

Who gets heat rash?

  • People who have outdoor occupations or jobs exposing them to great heat may be more susceptible to heat rash as well as other heat related conditions and illnesses. The Centers for Disease Control and Prevention have a guide for workers exposed to heat stress to help prevent such heat related problems.

  • People who wear heavy or tight clothing which does not breathe.

  • People with certain diseases or conditions such as cystic fibrosis, psoriasis, and eczema.

  • Getting severely sunburned can make it more likely that you may also suffer from heat rash.

  • Individuals who are obese may develop heat rash due to trapped heat in folds of skin.

  • People who are drinking alcohol are also more prone to developing a heat rash.

  • People who are taking certain medications including some antipsychotic drugs or medications with anticholinergic effects such as those for Parkinson's disease.

  • People who live in hot and humid conditions such as tropical climates.

What can be done about heat rash?

First of all know that heat rash is usually a temporary condition which usually goes away within a few hours to a few days. See your doctor if your rash does not go away or worsens after several days. Also see your doctor if you develop other symptoms in addition to the rash such as dizziness, rapid pulse, nausea, fever or chills, or you have signs of infection such as increased inflammation, pain, or pus coming from any blisters or bumps.

If your heat rash is not severe the following remedies may help:

  • Wash the sweat off with a mild soap like Dove.

  • Get into an air conditioned environment if you are able. Go to a mall, public library, movie theater or other cool environment to cool off.

  • Keep the affected skin area dry. Some people use baby powder to keep things dry.

  • Calamine lotion may decrease the itching sensation.

  • Drink lots of water to stay hydrated and to regulate your body temperature.

  • If you see your doctor topical steroids or antibiotics may be prescribed in more severe cases.

It is likely that we will continue to experience a long and hot summer. Please stay cool and protect yourself from the sun and heat as best as you are able. Remember if you develop a rash which you cannot explain it is always best to consult with your doctor or dermatologist. I always say, "When in doubt, let a doctor check it out"


  • Centers for Disease Control and Prevention: Heat Stress
  • The American Osteopathic College of Dermatology: Miliaria

  • Beers, M.H. et al (Eds.), (2003). The Merck manual of medical information second home edition. New York, New York: Merck & Co., Inc.