Heat rash (also called prickly heat or miliaria) happens when sweat gets trapped in blocked sweat ducts, usually during hot, humid weather or after heavy sweating. It can look like tiny red bumps or small blisters and often feels itchy, prickly or stinging—especially where skin rubs or clothing holds in heat, such as the neck, chest, back, under the breasts, groin, armpits, waistline and skin folds.
If you’re shopping for heat rash relief, the aim is to cool the skin, reduce friction and soothe itching while the rash settles. Start with cooling steps (cool shower, cool compresses, breathable clothing) and avoid thick, greasy products that can trap heat. Then choose a format that matches your main symptom—soothing lotions like calamine for surface irritation, or an oral antihistamine if itching is disruptive (particularly at night). If you’re pregnant or breastfeeding, buying for a child, or taking regular medicines, ask a pharmacist for tailored advice.
Shop by heat rash type
Popular types of heat rash products
- Calamine lotion: a classic choice for soothing itch and minor irritation on the skin’s surface.
- Anti-itch creams: targeted options for bothersome itching (follow label directions and suitability).
- Oral antihistamine tablets: often used when itching is disruptive; some can cause drowsiness.
- Antihistamine liquids/syrups: an alternative format if tablets aren’t suitable (check age guidance).
- Gentle body skincare: mild cleansers and light moisturisers that won’t feel heavy in the heat.
How to choose the right option
- If your skin feels prickly and irritated: cool the area first, then use a soothing lotion such as calamine.
- If itching is keeping you awake: consider an oral antihistamine that’s suitable for you (check drowsiness warnings).
- If the rash is in skin folds or under the breasts: prioritise cooling, keep the area dry, and choose light, non-greasy products.
- If you’re buying for a child or baby: use only age-appropriate products and dosing; ask a pharmacist if unsure.
- If you take regular medicines or have long-term conditions: check interactions and eligibility before choosing.
- To help prevent it returning: wear loose cotton or moisture-wicking fabrics, take breaks from heat, and change out of sweaty clothing promptly.
Quick links: common needs
FAQs
What is heat rash (prickly heat)?
Heat rash is a skin irritation caused by blocked sweat ducts, which traps sweat under the skin. It commonly appears as tiny red bumps or small blisters with a prickly, itchy or stinging sensation.
Is heat rash contagious?
No—heat rash isn’t contagious. It’s linked to heat and sweating rather than an infection. If the skin becomes increasingly painful, warm, swollen, or starts oozing pus, seek advice as this can suggest infection.
Heat rash vs hives or an allergy: how can I tell?
Heat rash usually shows as small bumps in sweaty or rubbed areas and tends to improve with cooling. Hives (urticaria) are often raised, wheal-like patches that can appear and fade quickly and may be linked to triggers such as foods, medicines or infections. If you’re unsure, the rash is widespread, or you have swelling of the lips/face or breathing difficulty, seek urgent medical help.
Where does heat rash commonly appear?
It often affects warm, sweaty areas or skin folds such as the neck, chest, back, under the breasts, groin, armpits, waistline and anywhere clothing traps heat.
Heat rash under the breasts: what helps?
Cooling and friction reduction are key. Keep the area clean and dry, wear a breathable, supportive bra, and change out of sweaty clothing promptly. Light, soothing products may help comfort, but avoid heavy ointments that can trap heat.
How can I calm heat rash quickly at home?
Move somewhere cool, take a cool shower, pat the skin dry, and wear loose breathable clothing. Cool compresses can help with comfort. Try to avoid heat, friction and heavy, greasy products while the rash settles.
Can I use hydrocortisone for heat rash?
Some mild steroid creams are used for certain inflammatory skin conditions, but they are not always the best choice for heat rash. Because suitability depends on the area of skin, age, duration, and your medical history, it’s best to ask a pharmacist or GP before using hydrocortisone—especially on the face, genitals, broken skin, or for children.
When should I speak to a pharmacist or GP?
Get advice if the rash is very painful, blistering, rapidly spreading, lasts more than a few days despite cooling measures, or shows signs of infection (increasing redness, warmth, swelling, pus, fever). Seek urgent help if you feel very unwell or have symptoms of a severe allergic reaction.
Safety notice: This information is for general guidance and does not replace personalised medical advice. Always read and follow the label for any medicine or medicated skin product. If you’re pregnant or breastfeeding, buying for a child, have a long-term condition, or take regular medicines, ask a pharmacist or GP for advice on the most suitable option.
