Ice can be added to the water in the reservoir, creating the perfect chilled temperature for absinthe.
Rather than emptying the fountain straight after using it, it is recommended to leave it overnight, avoiding any small risk, however rare, of thermal shock to the glass.
Contrary to what one might assume, absinthe fountains actually arrived very late in its history, carafes having been used before. It is thought that they were introduced by the absinthe-makers Cusenier in 1886, trying to give absinthe a healthy image. Water at the time was not the best quality, and so the fountains also contained a filter to remove impurities.