A sponge bath with lukewarm water may help. Never use cold water, ice, or rubbing alcohol. Dress your child lightly and don’t pile on blankets. Watch for signs of dehydration. Call the doctor immediately or go to the emergency room if your infant has dry diapers, a dry mouth or tongue, a dark red or purple rash, or is not feeding well. For an older child, call the doctor if they appear dehydrated, is not urinating enough, is not drinking well, or is not acting normally.