Thermal medical blanket using internal subtube

In a pneumatic, disposable, temperature control blanket receiving conditioned air through an external air supply connection wherein the blanket comprises an upper elongated flexible sheet and a lower elongated flexible sheet, the sheets being sealed together at their peripheries to define an elongated envelope having a length defined by first and second ends, and having lateral edges and a central region intermediate the lateral edges, a plurality of air flow openings defined within the lower sheet, and an inlet air port defined in the envelope for supplying pressurized air to the envelope, the improvement comprising a plurality of spaced fasteners interconnecting the upper and lower sheets intermediate the envelope ends and lateral edges, an elongated flexible conduit within the envelope of lesser transverse cross sectional area than the envelope disposed lengthwise to the envelope length intermediate said fasteners and in communication with the inlet air port, said conduit having lateral sides, and a plurality of air orifices defined only in said conduit lateral sides along its length whereby air received within said conduit is distributed along the length of the interior of the envelope, said conduit being of lesser transverse cross sectional area than the envelope when pressurized whereby a space exists between the majority of the circumference of said conduit and the envelope upon said conduit and envelope being pressurized whereby said conduit will be substantially surrounded by air of the temperature within the envelope.