The infrared signatures from hot engine parts pose major threats to military aircraft survivability. Reducing the skin temperature at the rear of the fuselage is key to reducing susceptibility to heat-seeking armaments. A heat shield placed between the nozzle wall and the outer casing of the engine can decrease the skin temperature at the rear of the fuselage. Therefore, numerical modeling of the fluid flow fields coupled with the radiative and conductive processes within the heat shield, nozzle, and casing were performed to determine the temperature distribution at the rear of the fuselage. The effect of the material properties and the dimensions of the heat shield were studied in order to determine their effects on the susceptibility of an aircraft.