Wis. Stat. § 134.81: Water heater thermostat settings.

No person who manufactures water heaters may sell any new water heater designed for use in a dwelling unit, as defined in s. 101.61 (1), unless that person does all of the following:

(1) Sets the thermostat of the water heater at no higher than 125 degrees Fahrenheit or at the minimum setting of that water heater if the minimum setting is higher than 125 degrees Fahrenheit.

(2) Attaches a plainly visible notice to the water heater warning that any thermostat setting above 125 degrees Fahrenheit may cause severe burns and consume energy unnecessarily.