Hot tap water is a common source of household burn injury. The charts of all patients hospitalized for tap water scalds in Dane County, Wisconsin, during a ten-year period were reviewed. Of 33 patients, 29 (88%) had readily identifiable risk factors: 17 (52%) were children younger than 5 years; three (9%) were older than 65 years; ten (30%) were physically or mentally disabled. One additional person was burned in a nonhome environment. Of the five deaths, three occurred in children younger than 30 months, and two occurred in patients older than 70 years. Almost all of these injuries could have been prevented by lowering the temperature of the household water heater to below 54.4 degrees C (130 degrees F) and preferably between 48.9 and 51.7 degrees C (120 to 125 degrees F). Physicians can play an important role in the prevention of this type of injury.