Should the water in your pool get below 10ºC the unit will come up with an alert to notify you. During the process of electrolysis, very cold water can cause damage to the titanium plate material within the cell.
To combat this the Naked system will automatically drop the OXI (oxidiser) output to 10% (from 100%) to protect itself. As soon as the water increases above 10ºC again the alert will go off and the system will set the OXI back to 100% or it's previous default.
More information can be found HERE.