When it comes to the warming and cooling presets on your Wave 2 device, the factory settings start out with the dotted button being for cooling and the blank button for warming.
However, you are able to set each button either to your favorite cooling session on the dotted button or favorite warming session on the blank button. You are even able to set both buttons to both be either cooling or warming!
That being said, in the event that both of your presets are cooling or both are warming and you try to revert back to one button for warming and the other for cooling, you'll receive an error message if you try to set the wrong temperature to the wrong button (ie. warming on the dotted button and cooling on the blank button).