Sweat production is one of the ways your body regulates its own temperature. Sweat is produced by small glands located throughout your body. Regulated by the brain, these glands release sweat via ducts on your skin. The sweat then evaporates to help cool down your body.
Heat rash, sometimes referred to as “heat stress” or “sweat rash,” occurs when sweat ducts become clogged and inflamed. Blocked ducts cannot release sweat, causing moisture to become trapped beneath the skin surface. The trapped moisture may cause rash-like symptoms, such as raised bumps, coarse skin texture, and discomfort.
Knowing how to spot heat rash can help you and your doctor pinpoint the best heat rash treatment.
Never Miss a Beat!
Subscribe to Our HealthBeat Newsletter!
Thank you for subscribing!
You can now select the specific newsletters you'd like to receive.
You are already subscribed.
Subscribe to more newsletters in our email preference center.
Sorry, an error occurred. Please try again later.
Get Healthy Tips Sent to Your Phone!
What Causes Heat Rash?
Heat rash, also called “prickly heat” or “miliaria,” is a skin condition that can affect babies, children, and adults in hot weather. The rash usually occurs when your sweat ducts become blocked and perspiration is trapped under your skin. People often experience this condition in the summer or in humid climates.
Babies are especially susceptible to this condition when their parents dress them in clothing that is too heavy for the temperature. Adults, however, also can experience heat rash when they overdress or spend too much time outside in hot, humid weather.
RELATED: What’s the Difference Between Sunburn and Sun Poisoning?
The symptoms are easy to detect. A common sign is a cluster of red bumps that resemble pimples on the skin. The red bumps, which can look like blisters, typically pop up on the neck, chest, and arms. They tend to accumulate in places with creases, such as in elbow creases and armpits, or under the breasts.
Some types of heat rash can make you feel an itchy or prickly sensation on your skin. In addition, it can range in severity, so consult your doctor if your symptoms are severe. Symptoms may include:
- Bumpy, itchy, and/or blister-like rash.
- Flesh-colored bumps.
- Burning sensation along skin.
- “Crawling” or prickly sensation on skin.
- Itchy sensation on skin.
- Pus formation around blisters or lesions.
Heat Rash Treatment
The best treatment depends on the severity of the rash.
In many cases, moving from the warm environment to a cooler, less humid area will resolve the issue, according to the Centers for Disease Control. Consider using a dusting powder to promote comfort, and an anti-itch cream or spray to help relieve itching and discomfort.
If your symptoms worsen or last longer than a few days, it may be time to visit your doctor. Prolonged symptoms could mean the heat rash has become infected.
Look for signs of infection, including:
RELATED: Hydration 101: What You Need to Know
Heat rash is a treatable condition when you know what to look for and how to take care of it. For more information on heat-related illnesses and how they affect skin care, contact the UPMC Department of Dermatology.
Editor's Note: This article was originally published on , and was last reviewed on .
Connect with UPMC
Headquartered in Pittsburgh, UPMC is a world-renowned health care provider and insurer. We operate 40 hospitals and 800 doctors’ offices and outpatient centers, with locations throughout Pennsylvania, Maryland, New York, West Virginia, and internationally. We employ 4,900 physicians, and we are leaders in clinical care, groundbreaking research, and treatment breakthroughs. U.S. News & World Report consistently ranks UPMC Presbyterian Shadyside as one of the nation’s best hospitals in many specialties and ranks UPMC Children’s Hospital of Pittsburgh on its Honor Roll of America’s Best Children’s Hospitals. We are dedicated to providing Life Changing Medicine to our communities.