The most common areas for prickly heat are the trunk and thighs. Reducing sweating usually controls the problem. The affected area is often pink or bluish white, and in severe cases the skin may be cracked, scaly, and soft, especially on the feet. Clammy hands and feet are a normal response to anxiety, and heavy sweating is normal when a person has a fever. However, frequent heavy sweating all over the body warrants medical attention because it can be a sign of an overactive thyroid, a low blood sugar level, or an abnormality in the part of the nervous system that controls sweating.
Blood tests can determine if thyroid function or blood sugar is abnormal.
Treatment Heavy sweating of the palms, soles, or armpits can be controlled to some degree with a nighttime application of aluminum chloride solution. A person first dries the sweaty area, then covers it with the solution, and then covers it with a thin plastic film. In the morning, the person removes the film and washes the area. If the solution irritates the skin, the plastic film should be left off. A solution of methenamine also may help control heavy sweating.