A cooling assembly for cooling a device, comprising: hermetic walls extending around and defining an enclosed vapor chamber configured to hold a liquid phase and a gas phase of a working fluid inside the vapor chamber, the vapor chamber extending along at least two orthogonal dimensions, wherein the enclosed vapor chamber comprises two opposing plates (16, 18) as hermetic walls, and wherein at least one of the two opposing plates (16, 18) is configured to conduct energy from the device to the inside of the vapor chamber; an interior porous wick structure disposed inside and lining one or more interior surfaces of the hermetic walls, the interior porous wick structure including pores (708, 1900) that are configured to hold the liquid phase of the working fluid inside the vapor chamber; and an exterior wick structure lining one or more exterior surfaces of the hermetic walls outside of the vapor chamber, the exterior wick structure including pores (708, 1900) that are configured to hold a liquid phase of a cooling fluid outside of the vapor chamber wherein the pores (708, 1900) of the interior porous wick structure are configured to hold the liquid phase of the working fluid inside the vapor chamber until heat from a heat source external to the vapor chamber vaporizes the liquid phase of the working fluid inside the vapor chamber into the gas phase inside the enclosed vapor chamber; and the exterior wick structure is configured to hold the liquid phase of the cooling fluid outside of the vapor chamber until at least some of the heat from inside the enclosed vapor chamber vaporizes the liquid phase of the cooling fluid in the exterior wick structure outside of the vapor chamber into the gas phase outside of the enclosed vapor chamber for transferring the heat from the heat source away from the heat source; characterized in that each of the two opposing plates (16, 18) is a non-planar wall (2216, 2218) including protrusions extending away from a plane primarily defined by the plate (16, 18) toward the other opposing plate (16, 18). hermetic walls extending around and defining an enclosed vapor chamber configured to hold a liquid phase and a gas phase of a working fluid inside the vapor chamber, the vapor chamber extending along at least two orthogonal dimensions, wherein the enclosed vapor chamber comprises two opposing plates (16, 18) as hermetic walls, and wherein at least one of the two opposing plates (16, 18) is configured to conduct energy from the device to the inside of the vapor chamber; an interior porous wick structure disposed inside and lining one or more interior surfaces of the hermetic walls, the interior porous wick structure including pores (708, 1900) that are configured to hold the liquid phase of the working fluid inside the vapor chamber; and an exterior wick structure lining one or more exterior surfaces of the hermetic walls outside of the vapor chamber, the exterior wick structure including pores (708, 1900) that are configured to hold a liquid phase of a cooling fluid outside of the vapor chamber wherein the pores (708, 1900) of the interior porous wick structure are configured to hold the liquid phase of the working fluid inside the vapor chamber until heat from a heat source external to the vapor chamber vaporizes the liquid phase of the working fluid inside the vapor chamber into the gas phase inside the enclosed vapor chamber; and the exterior wick structure is configured to hold the liquid phase of the cooling fluid outside of the vapor chamber until at least some of the heat from inside the enclosed vapor chamber vaporizes the liquid phase of the cooling fluid in the exterior wick structure outside of the vapor chamber into the gas phase outside of the enclosed vapor chamber for transferring the heat from the heat source away from the heat source; characterized in that each of the two opposing plates (16, 18) is a non-planar wall (2216, 2218) including protrusions extending away from a plane primarily defined by the plate (16, 18) toward the other opposing plate (16, 18).