• Heat rash is a form of skin irritation caused by excessive sweating during hot and humid weather. The condition may happen to people of any age, although it is more common in young children.
• Heat rash is also referred to as, ‘prickly heat,’ and is harmless, but involves a very itchy skin rash with small red spots all over the affected areas of a person’s skin. Heat rash may even include water blistering.
• It is caused by the blockage and inflammation of a person’s sweat ducts during times when they are exposed to both heat and high levels of humidity. The person’s blocked sweat ducts cause sweat to escape from their body into adjacent tissues, producing the prickling and itching sensations the person feels which are associated with the condition.
• A person’s forehead, often underneath a visor or a cap, in body folds, their chest, upper back, or on their arms, are commonly affected by heat rash. Small red spots appear on areas of the person’s body where sweat collects to include the person’s armpits, groin, the bend of their elbows and knees, or their waist. Mild swelling and redness can occur in the areas that are affected.
• A heat rash appears like a cluster of red pimples, or small blisters. The rash is more likely to appear on a person’s upper chest or neck, in their groin area, under their breasts, or in the creases of their elbows. Many times a heat rash will appear in the moist skin folds of a person’s arms, legs, neck, or at the person’s waistline or buttocks. Bands of red areas may occur, patches of reddened areas, or blistering.
• Heat rash is the result of humid and hot weather conditions and skin contacting itself, as well as clogged pores. Clothing and diapers can aggravate the condition. Plastic diaper pants or disposable diaper plastic can irritate a child’s skin surface, increasing the stimulus to the child’s sweat glands. The rash can seem very similar to that caused by infected hair follicles in appearance, although there are no hair follicles in heat rash bumps.
• The best form of treatment for heat rash is to provide the affected person with a cooler and less humid environment. It is important to keep the affected area of the person’s skin dry. Dusting the area of affected skin with powder might provide the person with comfort. Treating a heat rash can be simple and usually does not require medical intervention.

Source: disabledworld.com