A polymerization and tempering device (10) comprising at least one light source (60) which emits light in the visible and/or ultraviolet wavelength range, and comprising a fan (30), a light chamber (24) and with a door to the light chamber is provided, wherein the polymerization and tempering device is light-proof and the fan is arranged in an air channel (14) which extends through a housing (12) of the polymerization and tempering device (10) and in particular blows air behind at least the light source wall (56).
