A headlight for a vehicle with a cooling device for a semiconductor illuminant, wherein the cooling device comprises a fluid circuit with an evaporator, on or in which the semiconductor illuminant is arranged and a cooling medium can be evaporated, and wherein the cooling device further comprises a condenser on or in which the cooling medium can be condensed. The cooling medium comprises a first coolant, which has a first lower evaporation temperature and the cooling medium comprises a second coolant, which has a second higher evaporation temperature.