When the skin reacts to heat

Short answer: Heat and moisture together can cause redness and itching, especially where skin touches skin. The cause is friction and moisture rather than the heat itself. A thin, smooth layer between the skin surfaces and a fabric that moves moisture often help the most.

Skin on skin is the problem

Where two skin surfaces meet, heat and moisture build up at the same time. This usually happens between the thighs, under the arms and under the chest. When skin rubs against skin in the heat, it quickly turns red and sore. Soft trousers that cover the thighs can stop that rubbing. See bamboo sweatpants for women.

A smooth layer in between helps

A thin, smooth fabric between the skin surfaces takes away the friction. The fabric glides where skin would otherwise rub, and that makes a clear difference on a warm day. Choose a layer that sits flat without folds and does not squeeze. See bamboo sweatshirts for women for cooler evenings.

Keep the area dry

A fabric that moves moisture keeps the skin drier and calmer. When moisture stays put, the skin softens and becomes more sensitive to friction. A set that absorbs moisture and dries quickly is a good choice for warm days and active hours. See bamboo jogging suits.

Loose or close fitting

Loose clothing lets air in but can fold and rub. Close-fitting clothing stays put but can hold heat. The best option often lies in between: a thin layer that follows the body without squeezing and does not shift when you walk. Try things out and notice where your skin reacts.

Change when clothes get damp

Clothes that have been damp for hours keep rubbing against the skin. Bring a clean set if you will be out in the heat all day, and change when the first one feels clammy. A change in the middle of the day gives your skin a break and makes the afternoon more comfortable.

Seams and edges

It is often seams and edges that chafe when skin is warm and damp. Look for clothes with flat seams and edges that lie smoothly. Avoid hems that dig into the thighs or under the arms. An edge that stays flat rubs less than one that rolls up.

Washing and care

Detergent residue can make things worse for skin that is already irritated. Use a mild, unscented detergent, dose by the instructions and skip the fabric softener. Wash at a low temperature and let clothes dry fully. That way the fabric stays smooth and soft against the skin.

When redness does not go away

Clothing can remove much of the friction and moisture that cause redness, but it cannot fix everything. If the redness does not fade when the area is kept dry, or if sores appear, it is a good idea to talk to your doctor.

Frequently asked questions

Why does skin react in the heat

Because heat and moisture together create friction where skin touches skin. It is rarely the heat itself, but the mix of moisture and rubbing.

What can you do

Place a thin, smooth layer between the skin surfaces and choose a fabric that moves moisture away from the area. Change clothes during the day if they get damp.

When should you talk to your doctor

If the redness does not fade when the area is kept dry, or if sores appear. A doctor should look at it, so talk to your doctor.