A device for conditioning blood comprising: a heat exchanger module including a heat exchanger fiber layer including heat exchanger fibers configured to receive a heat exchanger fluid and exchange heat with the blood; a gaseous micro-emboli removal module including a micro-porous fiber layer including micro-porous fibers configured to receive atmospheric or sub- atmospheric pressures such that at least some gaseous micro-emboli are drawn from the blood through the micro-porous fibers; a gas exchanger module including a gas exchanger fiber layer including gas exchanger fibers configured to receive a gas mixture and exchange gas with the blood; and a potting material body that embeds the heat exchanger fibers, the micro-porous fibers and the gas exchanger fibers and defines a blood compartment that extends through the heat exchanger module, the gaseous micro-emboli removal module, and the gas exchanger module; characterized by at least one of: the heat exchanger module including stacked heat exchanger hollow fiber mat layers, wherein the heat exchanger hollow fiber mat layers are alternatively orthogonally angled from one another; the gaseous micro-emboli removal module including stacked micro-porous hollow fiber mat layers, wherein the micro-porous hollow fiber mat layers are alternatively orthogonally angled from one another; and the gas exchanger module including stacked gas exchanger hollow fiber mat layers, wherein the gas exchanger hollow fiber mat layers are alternatively orthogonally angled from one another. a heat exchanger module including a heat exchanger fiber layer including heat exchanger fibers configured to receive a heat exchanger fluid and exchange heat with the blood; a gaseous micro-emboli removal module including a micro-porous fiber layer including micro-porous fibers configured to receive atmospheric or sub- atmospheric pressures such that at least some gaseous micro-emboli are drawn from the blood through the micro-porous fibers; a gas exchanger module including a gas exchanger fiber layer including gas exchanger fibers configured to receive a gas mixture and exchange gas with the blood; and a potting material body that embeds the heat exchanger fibers, the micro-porous fibers and the gas exchanger fibers and defines a blood compartment that extends through the heat exchanger module, the gaseous micro-emboli removal module, and the gas exchanger module; characterized by at least one of: the heat exchanger module including stacked heat exchanger hollow fiber mat layers, wherein the heat exchanger hollow fiber mat layers are alternatively orthogonally angled from one another; the gaseous micro-emboli removal module including stacked micro-porous hollow fiber mat layers, wherein the micro-porous hollow fiber mat layers are alternatively orthogonally angled from one another; and the gas exchanger module including stacked gas exchanger hollow fiber mat layers, wherein the gas exchanger hollow fiber mat layers are alternatively orthogonally angled from one another. the heat exchanger module including stacked heat exchanger hollow fiber mat layers, wherein the heat exchanger hollow fiber mat layers are alternatively orthogonally angled from one another; the gaseous micro-emboli removal module including stacked micro-porous hollow fiber mat layers, wherein the micro-porous hollow fiber mat layers are alternatively orthogonally angled from one another; and the gas exchanger module including stacked gas exchanger hollow fiber mat layers, wherein the gas exchanger hollow fiber mat layers are alternatively orthogonally angled from one another.