We report the results of a study conducted recently at the Diamond Headache Clinic, Chicago, on the effectiveness of application of cold as an adjunctive therapy for acute headache. Ninety clinic outpatients were divided evenly into three groups according to headache type--migraine, cluster, and mixed. They used the standard headache medication for two attacks and the standard medication plus application of cold with a reusable, frozen gel pack for two attacks. There was no significant difference in patient response to the gel pack by headache type. Seventy-one percent of patients considered the pack effective; 52% reported an immediate decrease in pain, and 63% reported an overall decrease in pain. Seventy-one percent of patients intended to use the gel pack in the future. Use of such gel packs, which are available commercially, does not damage the skin. Our study indicates that cold application does provide some symptomatic relief of headache; it may also offer psychological alleviation of the pain.