Immersion of a hand in water at 38-40 degrees C for half an hour was performed in two phases with a one year interval in 38 patients with Hansen's disease and 20 controls. In all 20 controls wrinkles were produced. However, 32 of the 38 patients failed to show wrinkles in the fingertips. In 12, who participated in both phases, results of the second test confirmed those of the first. This may be an indication of irreversible damage. Due to the small number of individuals tested, no conclusions may be drawn in reference to groups and types of the disease. Provided that these results can be confirmed in larger groups of patients, this method could prove to be a tool in the diagnosis of Hansen's disease. Since the test is very easy to perform, it would be of great value in areas far from specialized medical centers.