10 and one of the layers 13 a 13 b in some embodiments the compressible material 14 is positioned between the element 10 and the layer which is not in contact with the patient extremity for example in fig2 layer 13 a serves as an outer layer and layer 13 b serves as an inner layer in contact with the patient extremity examples of suitable compressible materials include but are not limited to foam rubber foam plastic and a high loft non woven polymeric material when the heater 100 is secured around the extremity the compressible material 14 presses against the heating element 10 and presses it into closer contact with the skin this close contact with the skin optimizes conductive heat transfer from the element 10 to the skin and optimizes the efficiency of the heat transfer for any given temperature the efficient heat transfer allows the heater to be operated at lower temperatures and still be clinically effective the close contact also maximizes the uniformity of the temperature across the heater this is important because areas of the heater that do not contact the skin can undesirably become excessively hot the compressible material 14 also helps to make the fit more comfortable for the patient alternately or additionally the heater 100 can include a heat permeable standoff material not shown to diffuse heat from heating element 10 towards the layer 13 b in contact with the extremity for example a metal foil can be provided.