Nancy DeLoye Fitzroy was a widely recognized expert in thermal engineering, heat transfer, and fluid flow, amassed over a long career with General Electric. Fitzroy developed advanced heat transfer concepts for space vehicles, satellites, home appliances, air conditioning, jet engines, gas turbines, steam turbines, nuclear reactor cores, motors, and many other diverse types of equipment. She is considered both a chemical and a mechanical engineer. Equal to her technical accomplishments was her dedication to expanding the applied literature on heat transfer and fluid flow. Fitzroy is recognized as the first chemical engineering woman graduate at Rensselaer Polytechnic Institute and attained nationwide prominence as the first woman president of the American Society of Mechanical Engineers. She was inducted into the National Academy of Engineering and contributed to the image of women as engineers through career encouragement to women pursuing engineering. She was recognized by the Society of Women Engineers with the 1972 Achievement Award.