The F-35 and F-22 may be among the world’s most advanced stealth fighters, but they cannot hide one thing: heat. When heat-seeking missiles lock onto aircraft, fighters release flares to confuse infrared sensors and break missile tracking. But the infrared signals produced by fighters, including heat from engine exhaust and air friction over the fuselage, are different from those generated by flares. These heat signatures could provide valuable infrared information for target detection and...