The use of infrared radiation to reduce heat loss in burned patients: experiments with a phantom.

Heat losses from patients with severe burns place considerable demands on the body. The metabolic rate, already elevated as a result of the injury, must rise further to maintain thermal equilibrium. To compare different methods of supplying heat to burned patients, a phantom has been constructed in which a free water surface has been used to simulate burned tissue. The effect of environmental temperature, humidity and air velocity, and of radiant energy, on the evaporation rate from the water surface, and on the energy supplied to the water to maintain its temperature, have been measured. Results showed that humidity and air velocity were the main factors determining evaporation. The internal energy required to maintain the temperature of the phantoms could be reduced by use of infrared radiation. This is particularly appropriate in the clinical situation, as energy is supplied to the skin surface, where it can replace directly energy lost through evaporation. Because the effect of radiant energy on the evaporation rate was small, it may be possible to create a microclimate around a patient where air velocity can be set to give a desired rate of evaporation, and the infrared level can be adjusted for patient comfort.