Four types of bipolar integrated circuits were irradiated at different elevated temperature with two different dose rates, after that, the corresponding sensitive parameters were extracted and analyzed. The results prove that elevated temperature irradiation could provide a conservative estimation for the radiation damage at low dose rate when the optimum irradiation temperature is selected. The optimum irradiation temperature increases with the dose rate but decreases with the total dose. With the same total dose and dose rate, the optimum irradiation temperatures of bipolar integrated circuits with NPN input stage are lower than those with PNP input stage.