Pain threshold and heat stress reaction of mice irradiated by high power millimeter wave

Heat stress reaction was induced by irradiation of high-power 8 millimeter wave on both mice and rats. Four periods of their stress reaction——quiet period, guarding period, deadlock period, prostrating period were observed. The pain threshold temperature of a mouse is (43.1±1.8) ℃, which is not related with its weight, initial temperature of the skin and irradiated power density. The temperature increase of the skin was (8.4±1.0) ℃ by the irradiation at the power density of 3.5 W/cm2 for 3 s and it was (21.1±3.0) ℃ at the power density of 7.0 W/cm2 for 3 s. The duration of guarding period was measured. The relations between the guarding duration and the surficial area of the mouse, the effective irradiating area and irradiating power intensity have been built. The experimental resu