Introduction Hot tap water scalds (TWS) can have devastating consequences and lifelong impact on survivors. Collaborating with bi-national, plumbing regulatory stakeholder organisations we undertook a study to (i) describe the frequency, demographic profile and in-hospital outcomes of people with TWS admitted to Australian and New Zealand burn centres.

Methods Patient demographic, care and outcome data were extracted from the Burns Registry of Australia and New Zealand for people with TWS admitted to Australian and New Zealand burn centres between January 2010, and December 2018.

Results Overall, there were 650 people with TWS admitted to an Australian and New Zealand burn centre during the study period. Australians with TWS (median [IQR] 29 [1–69] years) were older than New Zealanders (2 [1–36] years). Most TWS occurred in the home, and 92% of injuries occurred in the bathroom. More than 55% of injuries occurred due to the accidental alteration of water temperature at the tap whilst the person was bathing. Two thirds of patients underwent a surgical procedure. Overall mortality rate was 3.7%, and the median hospital length of stay was 8.8 days.

Conclusion Tap water scalds remain a public health problem in Australia and New Zealand, particularly in high-risk age groups. Our research has highlighted opportunities to reduce risks of TWS by making changes to residential heated water regulations, as well as alterations to the design and installation of residential tap fixtures used for personal hygiene.

Learning outcomes Early collaboration across professional boundaries is valuable. This collaborative research has contributed to binational regulatory improvements. The 2022 Plumbing Code of Australia contains recommendations for the design and installation of tap fixtures in shower and bath recesses to prevent accidental alteration of water temperature whilst bathing. In NZ, regulators have proposed reducing the maximum allowable hot water temperature of personal hygiene taps in New Zealand homes to 50C from 55C, in line with Australian regulations.