The iced box is a wizard artifact combined with hydromancy. The ‘iced box’ had a wooden shell surrounding a special heat insulating stone. The stones are imported from Quarry as a refined material and finished with wizardry on Bethairia. Inside the insulating stone is a thin layer of wizard-enchanted malleon, which transfers the heat from the stored food or drinks into water cycled by a hydroshard. The hydroshard has several spells active within to cool the water which in turn cools the interior of the box. A tray sits just below the hydroshard to collect tiny ice crystals. The tray takes two hours to fill. A good-sized hydroshard only has to be replaced once every five years or so.
An older version uses pyroshards, but they are outlawed now.