Abstract: A heat exchanger for transferring heat between an external fluid and an internal fluid includes two or more heat exchange cells, each heat exchange cell having a top plate with an inlet aperture at one end thereof and an outlet aperture at the other end thereof, the top plate including a first surface, a second surface and peripheral edges. The heat exchange cell also includes a bottom plate juxtaposed with the top plate, the bottom plate having an inlet aperture at one end thereof and an outlet aperture at the other end thereof. The bottom plate includes a first surface, a second surface and peripheral edges. The peripheral edges of the top and bottom plates are attached to one another, the second surfaces of the top and bottom plates confronting one another and the inlet and outlet apertures of the top and bottom plates being in substantial alignment with one another. The attached top and bottom plates define a high pressure chamber between the second surfaces thereof.