A blood processing apparatus (150) comprising a housing (152), a heat exchanger core (170), a heat exchanger element (172) disposed about the heat exchanger core (170), a cylindrical shell (174) arranged coaxially about the heat exchanger element (172), a gas exchanger element (176) disposed about the cylindrical shell (120) and an elongate collector (180) in fluid communication with a shell aperture (178) such that blood may exit the cylindrical shell (174) through the shell aperture (178), may enter the elongate collector (180) and may flow through the gas exchanger element (176) in a circumferential direction.