Children are more likely to be hospitalised because of burns from hot liquids than from contact with fire and flames. Many of these hot liquid burns are from contact with hot tap water, usually in the home. Hot tap water burns to young children can be prevented completely by lowering the delivery temperature of the hot tap water. This study reports on the evaluation of a program designed to lower the temperature of home hot tap water in Dunedin, New Zealand. In conjunction with a national media campaign, the program provided an educational intervention to households with young children. Before and after measures were made and comparison groups were used to determine the effect of the intervention on tap water temperatures. Mean tap water temperature was 64.2 degrees C at baseline and 61.2 degrees C at follow-up. The proportion of households with water temperatures above 70 degrees C decreased by 50 per cent between baseline and follow-up while the proportion below 60 degrees C increased from 33 per cent to 47 per cent. The group receiving the intervention did not differ significantly from the comparison groups. There were significant decreases in tap water temperature across all groups, but the majority of households still had temperatures above 55 degrees C at the end of the study.