In 1987, CPSC helped develop requirements for temperature controls to make sure that spa water temperatures never exceed 104 degrees Fahrenheit.
~U.S. CONSUMER PRODUCT SAFETY COMMISSION
...most people like a shower temperature slightly warmer than body temperature, about 105ºF or 40ºC.
And here, my friends, is the cold water temp in my villa...
Yes, that reads 106° (41C)