Device for cooling a heat source of a motor vehicle

A device for cooling a heat source of a motor vehicle, comprising a cooling body (7) which is in thermal contact with the heat source, a first fluid stream for the discharge of heat being capable of flowing to the cooling body (7), wherein at least one second fluid stream for the discharge of heat can flow selectably to the cooling body (7), wherein the heat source is an electrical energy accumulator, the first fluid stream being driven by a compressor (1) of a refrigerating circuit and the second fluid stream being driven by a circulating pump (6), wherein the device is operable in a first mode wherein the compressor (1) is off and the at least one second fluid stream flows along a flow path defined by the circulating pump (6), a condenser (2) and the cooling body (7) so that the at least one second fluid stream receives heat from the heat source, and a second mode wherein the compressor (1) is on and the first fluid stream flows along a flow path defined by the compressor (1), an evaporator (5), the cooling body (7), and the condenser (2) so that the first fluid stream receives heat from the heat source.