Abstract: Various apparatus and methods for thermally managing a heat generating device. In one aspect, a method of thermally managing a heat generating device is provided that includes placing a heat exchanger in thermal communication with the heat generating device. The heat exchanger has an interior space. A membrane is in the interior space between a first chamber and a second chamber. The membrane has a gas impermeable portion and at least one gas permeable portion to enable vapor bubbles in the second chamber to pass through the membrane at the at least one gas permeable portion and into the first chamber. A liquid is moved through the second chamber.