The best things to put on a heat rash are calamine lotion, a low-strength hydrocortisone cream, or a cool damp cloth. Heat rash happens when sweat gets trapped under your skin because the ducts are blocked, so most treatments focus on cooling the skin, reducing itch, and keeping those ducts clear. The good news is that most heat rashes clear up on their own within a few days once you cool down and stop irritating the area.
Topical Treatments That Help
Calamine lotion is one of the most widely recommended options. It cools the skin on contact, reduces itching, and dries out the tiny bumps without clogging your pores further. Apply a thin layer directly to the rash and let it dry. You can reapply several times a day as needed.
Over-the-counter hydrocortisone cream (1%) works well for heat rashes that are red, inflamed, and intensely itchy. It calms the inflammation and takes the edge off the prickling sensation. Use it sparingly, applying a thin layer to the affected area up to twice a day. Avoid using it for more than a week without medical guidance, especially on your face or on a child’s skin.
Lotions containing menthol can also provide temporary cooling relief. The menthol creates a sensation of coolness that distracts from the itch and helps you resist scratching, which is important because scratching can break the skin and invite infection.
Cooling the Skin Directly
Sometimes the simplest approach is the most effective. A damp cloth or an ice pack wrapped in a tea towel, held against the rash for up to 20 minutes, can dramatically reduce discomfort. Cool baths and showers also help. Let your skin air-dry afterward rather than rubbing with a towel, which can further irritate inflamed skin.
An oatmeal bath is another option worth trying. Colloidal oatmeal (finely ground oatmeal sold at most drugstores) added to lukewarm water soothes irritated skin and reduces itching across larger areas of the body. This is especially useful when the rash covers your back, chest, or other hard-to-reach spots where applying cream is awkward.
Anhydrous Lanolin for Prevention
If you get heat rashes repeatedly, anhydrous lanolin is worth knowing about. This wool-derived fat acts as a barrier that actually helps prevent sweat ducts from getting clogged, unlike most heavy moisturizers that make the problem worse. Applying it before exercise or before heading into hot, humid conditions can stop new lesions from forming. One important caveat: if you’re sensitive to wool, skip this ingredient entirely.
What Not to Put on a Heat Rash
Choosing the wrong product can make heat rash worse by trapping more sweat underneath your skin. Avoid oily or greasy moisturizers, petroleum-based products, heavy cosmetics, and thick sunscreens. These all block pores and sweat ducts further, which is exactly the problem that caused the rash in the first place. Fragranced lotions and perfumed body washes can also irritate already-inflamed skin.
Beyond what you apply, what you wear matters too. Tight, synthetic clothing traps heat and sweat against your skin. Loose, breathable fabrics like cotton give the rash room to heal.
Treating Heat Rash on Babies
Babies are especially prone to heat rash because their sweat ducts are smaller and clog more easily. For infants, the safest approach is cooling the skin and removing the heat source. Move the baby to a cooler environment, remove extra layers of clothing, and let the skin breathe. A cool, damp washcloth pressed gently on the rash works well.
Be cautious about applying anything to a baby’s skin. Avoid hydrocortisone cream unless your pediatrician specifically recommends it, and stay away from greasy ointments or heavy creams. If you want to use a moisturizer, choose one with anhydrous lanolin, which helps keep sweat ducts open rather than sealing them shut. Calamine lotion is generally considered safe for older infants, but check with your child’s doctor first for newborns.
Signs the Rash Needs Medical Attention
Most heat rashes resolve within a few days once you cool down and keep the area dry. But a heat rash can sometimes develop a bacterial infection, particularly if the skin has been scratched open. Watch for bumps that fill with pus, skin that feels warm or swollen around the rash, fever, chills, or nausea. These are signs that bacteria have entered through breaks in the skin and you need treatment beyond what’s available over the counter.
If the rash hasn’t improved after a few days of home treatment, or if it’s visibly getting worse rather than better, that also warrants a medical visit. A persistent rash that doesn’t respond to cooling and topical care may be something other than heat rash, or it may have progressed to a deeper form that affects the sweat glands more severely.