Glazed or Iced donuts, even when finished properly may change in appearance relative to their environment. For example, chocolate iced donuts displayed in counter top open back cases may appear dull if the temperature inside the case is below 20C such as you may experience during winter months. Conversely, the same donut displayed in the same way during the summer months may become tacky, or worse the icing may melt and flow off the donut under extremely warm and humid conditions. Ideally, donuts should be merchandised in a display counter where the temperature remains between 20-25C and at least 15cm (8") below fluorescent lights.