Partial body exposure of human volunteers to 2450 MHz pulsed or CW fields: similarities in physiological response

Physiological thermoregulatory responses of heat production and heat loss were measured in two groups of adult volunteers during 45-min dorsal exposures of the body to 2450 MHz continuous wave (CW) or pulsed (PW) radio frequency (RF) energy. For both CW and PW exposure, two power densities (PD=27 and 35 mW/cm/sup 2/) were tested in each of three ambient temperatures (T/sub a/=24, 28 and 31/spl deg/C) plus T/sub a/ controls (no RF). No change in metabolic rate occurred. Esophageal temperature was regulated to within 0.1/spl deg/C of baseline levels by efficient sweating and increased skin blood flow. Of six measured skin temperatures, only the upper back (irradiated directly) increased significantly more during PW exposure than CW. With this single exception, no clear evidence for a differential response to CW and PW RF energy was found.