Changes of the rectal temperature during the day were determined in CBA mice and Wistar rats subjected to the total body irradiation with microwaves of different intensity. Dependence of these indices on keeping the animals in containers for irradiation and temperature reactions, and survival of the animals after exposure to UHF microwaves of various intensity were investigated. As shown, temperature rise and survival of the animals depended on the current intensity density and the action duration, the rectal temperature elevation during the irradiation; a pronounced reduction of this index following irradiation may be considered as a prognostic sign of affection with the UHF microwave field.