A heat-exchanger including a device for separating oil from a coolant-oil mixture and cooling the oil and cooling and/or liquefying the coolant. The heat exchanger features a first area cooling and/or liquefying the coolant, and a second area cooling the oil. The heat exchanger further features at least two manifolds. The first area of the heat exchanger features flow channels guiding the coolant, and the second area of the heat exchanger features flow channels guiding the oil. The flow channels extend between the manifolds. Each of the flow channels has a respective outside flooded by a heat-absorbing fluid.