I have been told by plumbers that the anti-scald devices keep hot water at just the right temperature for the growth of the bacteria responsible for Legionnaire’s Disease.
Oops I meant to write that lower temperature settings on water heaters meant the hot water was kept at a temperature that was just right for the growth of the bacteria. There are anti scalding devices that work to lower the temperature of water that is hot enough in the hot water tank to prevent the growth of the bacteria. My bad.