ASSE - Understanding Potential Scald Hazards From Water Heaters

Understanding Scald Hazards Presented by your Water Heater
Folks- this is big in the plumbing world. When something is big in the plumbing world it usually involves injury and lawyers. So pay attention to this one.
The maximum deliverable water temperature in a building is dictated by code because of numerous injuries to young children and especially elderly people. The big one we have almost all experienced is when were in the shower and someone flushed a toilet and stole the cold water. The typical reaction is to jump back out of the scalding water, but elderly people cant do this.
Here is a catch 22 for you. If the water heater is turned down low enough for the scalding issue to go away, its also then the perfect temperature for Legionellae bacteria to grow and that bacteria causes a pneumonia type disease, (picture a severe butt whipping case of pneumonia), and who are the most susceptible to this? why the same young and elderly we were trying to prevent from being scalded.
The American Society of Sanitary Engineers has devised solutions to this and you can read a short white paper on the subject here.
This is one of the reasons we have plumbing codes.