Heat rash — known as prickly heat or miliaria — is one of the most common summer skin problems in India. It develops when sweat ducts become blocked, trapping perspiration under the skin. Small red bumps and a prickling sensation appear on areas where sweat collects — the neck, chest, back, groin, and skin folds. It is uncomfortable but usually harmless and clears with simple home treatment.
Types of Heat Rash
- Miliaria crystallina — tiny clear blisters on the surface; common in babies
- Miliaria rubra — red, itchy bumps (classic prickly heat); most common in adults
- Miliaria profunda — deeper, flesh-coloured bumps; occurs with repeated overheating
Home Treatment Steps
Cool the skin immediately
Move to an air-conditioned or shaded area. A lukewarm — not cold — shower removes sweat and salt that block ducts. Apply cool, damp cloths to affected areas for ten minutes, several times daily. Fanning damp skin accelerates evaporation and cooling.
Keep the area dry and exposed
Let skin breathe. Avoid tight synthetic clothing that traps heat and moisture. Loose cotton is best. At home, leave affected areas uncovered when possible. Change out of sweaty clothes promptly after exercise or outdoor work.
Use calamine lotion
Calamine soothes itching and has a mild drying effect that helps clear superficial blisters. Apply with clean hands or a cotton pad. Avoid ointments and heavy creams — they trap heat and worsen blockage.
Light dusting powder — used correctly
A thin layer of prickly heat powder on dry skin can absorb moisture in humid conditions. Do not over-apply — thick caking blocks ducts further. Talc-free cornstarch-based powders are a safer alternative for some people concerned about talc inhalation.
Stay hydrated
Drink plenty of water and oral rehydration fluids in extreme heat. Dehydration reduces sweating efficiency and raises body temperature, worsening heat rash and heat-related illness.
Avoid irritants
Skip perfumed soaps, body lotions, and oils on affected skin until the rash clears. Do not scratch — it introduces bacteria and can cause infection. Trim children’s nails if they cannot resist scratching.
Heat Rash in Babies and Children
Infants are especially prone because sweat ducts are immature. Dress babies in one more layer than an adult would need — not more. Use cotton nappies and change frequently. Avoid powder on infants due to inhalation risk; focus on cooling and air exposure instead. If rash appears in skin folds, gently separate the folds during nappy changes and allow air drying. Most childhood heat rash clears within two to four days with cooling alone.
When to See a Doctor
- Rash with fever, chills, or feeling unwell — possible heat exhaustion
- Pus-filled bumps, spreading redness, or swollen lymph nodes — infection
- Rash not improving after four to five days of home treatment
- Deep, painful lumps — possible miliaria profunda needing assessment
- Infants with widespread rash, poor feeding, or lethargy