Legionaire’s Disease was finally tracked down to a general agreement and, in some cases, a requirement that scalding accidents could be avoided by adjusting all hot water faucets in medical facilities and care centers to a lower temperature, generally by lowering the water heaters from 140-150F to 120F; this turned out to be an ideal incubation temperature for the specific bacteria implicated in these cases.
Rather than invest in mixing faucets or some other method of preventing scalding while increasing heating temperatures, most facilities simply began super-chlorinating the water supply at the point of entry.
Now, everybody in those places drinks bottled water.