a low air loss bed having an integral source of air mounted to the frame thereof . sets of air bags are mounted on the frame , each set of air bags corresponding to a portion of the body of the patient to be supported on the bed . separate gas manifolds are provided , each of which connects a single set of air bags to the gas source . individually controlled valves are used to adjust the amount of air which flows to the gas manifolds and on into the air bags . also , means are provided operable to selectively route a flow of additional air to the gas manifold which supplies air to the air bags which support the heavier portions of the patient . a low air loss air bag is provided , as is apparatus for adjusting the amount of air supplied to each set of air bags and for controlling the temperature of the air delivered . also provided is a means for simultaneously fully inflating all the air bags and means for simultaneously deflating all the air bags .