The way in which water is distributed within the built environment has a profound effect on water safety. Keeping hot water hot and cold water cold is a fundamental element in managing the risks of exposure to harmful microorganisms that can develop in water systems and is perhaps of greatest significance in healthcare premises. A number of new hospital designs now incorporate circulating cold water as well as hot water systems and this is certainly a step in the right direction. The truly innovative pipe-within-a-pipe Eco-Duo design will only serve to improve the safety of hot and cold water in hospitals and anywhere else that it is installed.