Use of insulation to reduce extremity temperature nonuniformity during whole body hyperthermia in dogs.

Previously we have shown in dogs that tibial bone marrow and s.c. tissue temperatures are lower than rectal temperature during the plateau phase of whole body hyperthermia with the use of a radiant heating device. In an attempt to increase thermal dose to these sites during whole body hyperthermia, we applied insulation to an extremity prior to the plateau phase of heating. We found that extremity insulation during whole body hyperthermia resulted in increased s.c. tissue and tibial bone marrow temperatures. With insulation, tibial bone marrow and rectal temperature were nearly equal but s.c. tissue temperature, although greater than without insulation, remained lower than rectal temperature. High efficiency extremity insulation or supplemental heating techniques may be necessary during whole body hyperthermia with the use of the radiant heat device in order to assure that extremities receive the prescribed thermal dose.