First step

The temperature range is selected. This can be selected freely (as long as it falls within the comfortable temperature range stated above). In general, the visual perceived distance between the extreme depth levels will be assessed and the extreme temperatures selected accordingly (higher temperature difference for higher distances). However, if the simpler algorithm is to be used, then the extremes depth levels will always be linked to the extreme temperatures of 14 and 38 ◦C, regardless of their perceived relative distance.
