A heat exchanger for cooling a heat generating device including a base having a recess with a base coolant inlet opening and a base coolant outlet opening. A porous core is positioned within the recess of the base, and has a core coolant inlet opening and a core coolant outlet opening that are arranged in corresponding relation with base coolant inlet opening and a base coolant outlet opening so as to be in fluid communication. A porous gasket is pinched between the porous core and the base.