Effect of Exposure to a Radiofrequency Electromagnetic Field on Body Temperature in Anesthetized and Non‐Anesthetized Rats

Exposure to a radiofrequency (RF) signal at a specific absorption rate (SAR) of 4 W/kg can increase the body temperature by more than 1 °C. In this study, we investigated the effect of anesthesia on the body temperature of rats after exposure to an RF electromagnetic field at 4 W/kg SAR. We also evaluated the influence of body mass on rats’ body temperature. Rats weighing 225 and 339 g were divided into sham‐ and RF‐exposure groups. Each of the resulting four groups was subdivided into anesthetized and non‐anesthetized groups. The free‐moving rats in the four RF‐exposure groups were subjected to a 915 MHz RF identification signal at 4 W/kg whole‐body SAR for 8 h. The rectal temperature was measured at 1‐h intervals during RF exposure using a small‐animal temperature probe. The body temperatures of non‐anesthetized, mobile 225 and 339 g rats were not significantly affected by exposure to an RF signal. However, the body temperatures of anesthetized 225 and 339 g rats increased by 1.9 °C and 3.3 °C from baseline at 5 and 6 h of RF exposure, respectively. Three of the five 339 g anesthetized and exposed rats died after 6 h of RF exposure. Thus, anesthesia and body mass influenced RF exposure‐induced changes in the body temperature of rats. Bioelectromagnetics. 2020;41:104–112. © 2019 Bioelectromagnetics Society.