Burn wound evaporation--an evaluation of air diffusion resistances governing heat transfer in a clean air unit.

Heat losses from burned patients need to be reduced to avoid placing unnecessary demands on body metabolism. In order to allow more accurate assessments of heat loss, heat transfer has been studied in a clean air unit used for intensive care of burned patients. Evaporation rates have been measured from a phantom representing a recumbent human torso with burn wounds simulated by moist lint strips mounted on the surface. Heat transfer is determined by a complex interaction of free and forced convection, with evaporation rate being greatest on the side of the abdomen in free convection and towards the top in the forced case. Air diffusion resistances have been derived to describe evaporative heat transfer from different parts of a body. Equations have been fitted to data obtained under a wide range of conditions, and will be used to evaluate heat losses from burned patients in order to improve treatment conditions.