Heat Rash in Florida: What It Looks Like, How to Treat It and Rashes That Look Similar

Written by Cherlie Joseph, MSN, FNP-BC · Medically reviewed by Naurah Gaspard, DNP, FNP-C, FNP-BC · Updated November 2026

Heat rash (miliaria, or prickly heat) is a cluster of tiny itchy or prickly bumps that forms when sweat gets trapped under the skin. In Florida's heat and humidity it shows up most on the neck, chest, back, under the breasts, the groin and skin folds. It usually clears within a few days once you cool off and let your skin breathe.

What heat rash looks like

Heat rash happens when sweat ducts get blocked and sweat leaks into the skin. How deep the blockage is changes how it looks:

Type	What you see	How it feels
Crystal-like (most superficial)	Tiny clear bumps like water droplets	Usually not itchy
Red (prickly heat, most common)	Small red bumps, sometimes in clusters	Prickly, stinging or itchy
Deep (uncommon)	Firm, flesh-colored bumps	Less itchy; area may not sweat

On darker skin, bumps may look skin-colored, brown or gray rather than red. Heat rash appears where clothing traps heat, such as under a sports bra, a backpack or waistband, and in skin folds. Workers in hot uniforms and people who are sick in bed are at higher risk.

How to treat heat rash at home

• Cool down. Move to air conditioning or shade, and take a cool shower.
• Let your skin breathe. Change out of sweaty clothes; wear loose cotton or moisture-wicking fabric.
• Skip heavy creams and ointments on the rash. Thick products can block sweat ducts more.
• Calamine lotion or a cool compress eases itching and prickling.
• 1% hydrocortisone cream, used briefly as the label directs, can calm a very itchy patch.
• Do not scratch. Broken skin can get infected.

Most heat rash clears in 2 to 4 days once you stay cool. If it lasts longer, gets more painful or develops pus bumps, have it checked.

Rashes that look like heat rash

Florida summers bring several look-alikes. They often need a different treatment:

• Folliculitis: red or white pus bumps centered on hair follicles. "Hot tub folliculitis" appears 1 to 2 days after a hot tub or poorly chlorinated pool, often under the swimsuit.
• Yeast (intertrigo): bright red, moist, sometimes shiny rash in skin folds with small satellite spots. Needs an antifungal, and steroid creams can make it worse.
• Sun rash (polymorphous light eruption): itchy bumps on sun-exposed skin hours after sun, often early in the season.
• Hives: raised welts that move around within a day. See our hives guide.
• Seabather's eruption ("sea lice"): itchy bumps under the swimsuit after swimming in Florida's ocean, caused by tiny jellyfish larvae. Remove your swimsuit and shower right after leaving the water.
• Insect bites: scattered bumps, often on exposed skin, with a tiny center point.

Our rash identifier guide compares more rashes side by side.

Preventing heat rash in Florida

• Exercise outdoors early in the morning or in the evening.
• Choose loose, light-colored, breathable clothing; avoid tight synthetic layers that do not wick.
• Shower after workouts or yard work and change into dry clothes.
• Use light, oil-free sunscreen and lotions rather than heavy creams in hot weather.
• Keep skin folds dry; a little powder can help some people.
• Use fans and air conditioning at night, especially if you sleep hot.
• Drink water steadily through the day.

When heat is more than a rash

Heat rash itself is harmless, but it means your body is struggling with heat. The CDC lists signs of heat exhaustion: weakness, heavy sweating, headache, dizziness, nausea or vomiting. Move somewhere cool, loosen clothing, sip fluids and rest. Heat stroke is an emergency: body temperature of 104°F or higher with confusion, slurred speech, seizures or passing out.

Frequently asked questions

How long does heat rash last?

Most heat rash fades within 2 to 4 days once you cool down and keep the area dry. Rash that lasts longer or keeps coming back may be something else.

Is heat rash contagious?

No. Heat rash is caused by blocked sweat ducts, not an infection, so it cannot spread to others.

What is the fastest way to get rid of heat rash?

Get out of the heat, take a cool shower, wear loose dry clothing and avoid heavy creams. Calamine lotion can ease itching.

Sources

• CDC Yellow Book: Heat and Cold Illness
• MedlinePlus: Heat Illness
• American Academy of Dermatology: Rash 101 in adults

Keep reading

• Rash identifier guide
• Hives: causes and treatment
• Contact dermatitis and Florida plant rashes
• Browse all conditions and treatments A to Z

This article is for general education and is not a substitute for medical advice. Treatment, including any prescription, is decided by a licensed provider after reviewing your health history. OurTopClinic is not for emergencies; if you have a medical emergency, call 911. OurTopClinic serves adults located in Florida, New Mexico, Oregon and Washington. Learn more at ourtopclinic.com.