Prickly heat, or heat rash, is an out-break of tiny red bumps caused by impeded sweat glands. Perspiration that is unable to reach the skin’s surface literally breaks out in minute, itchy blisters.
The rash afflicts babies as well as obese people and those with skin disorders that hinder sweat-gland function. It tends to appear where sweat cannot easily evaporate in body folds or on skin covered or chafed by clothing or bedding.
To avoid it, adults should wear loose, light clothing; babies neither clothing nor blankets if feasible. Staying in a room with air conditioning or a fan helps. Take frequent baths or showers without soap. Baby powder or a powder containing talc will help to keep skin dry and to prevent chafing. Apply it sparingly so that it doesn’t cake. Don’t treat prickly heat with ointments or petroleum jelly.