Abstract: A device including an integrally formed membrane oxygenator and heat exchange device positioned in a single housing. The device includes a thermally conductive body formed with a plurality of blood pathways on its surface, and a gas permeable membrane, or membranes positioned in the housing in substantial contact with the heat exchange body to cover or lie within a portion of each of the pathways. The membrane defines a gas pathway separate from the blood pathway through which a gas is directed. The blood is directed through the individual blood pathways. The device also includes various ports and passageways for delivering the blood to the individual channels, and for collecting and removing the blood from the device.