Skin and subcutaneous temperature changes during exposure to intense thermal radiation

Abstract

Radiometric measurements have been made of the skin temperature changes occurring during irradiation of the body by high-intensity thermal radiation with square-wave pulses. A quartz lamp bank provided a source of color temperature of 2,650 K and a uniform (± 5%) irradiance of 0.16 cal/sec per cm2 over areas of 40 x 30 cm. A spring-operated focal-plane shutter controlled exposure times from 2–120 sec with a rise time of 0.01 sec. The radiometer, mounted between the quartz lamps so as to view the skin from normal incidence, had a 96% response time of 0.1 sec and a precision of ± 0.1 C. When corrections were made to allow for the far infrared radiation reflected from the skin, the radiometer gave accurate measurements of skin temperature during the periods of irradiation. Experimental values of skin temperature rise were compared with those calculated by the finite differences method for various skin layers using the best available values for optical and thermal properties of each skin layer. During the initial 10–15 sec of irradiation, theoretical and experimental values were in agreement, indicating passive response of the skin to thermal radiation. Subcutaneous temperatures, calculated from surface temperature data, indicated a high degree of penetration of the radiation 0.2–0.4 mm below the skin surface. mathematical model; infrared reflection by the skin; radiometric measurement of skin temperatures Submitted on September 2, 1964