Thermal, acoustics and lighting account for the greatest sources of discomfort in offices. Seldom have these three factors have been studied concurrently and outside of controlled laboratory settings. We conducted a longitudinal investigation of how temperature, acoustics and lighting affect physiological, behavioral and emotional state in an open office while subjects perform real-world tasks. The environmental, physiological, behavioral and emotional data were captured using sensors, wearables and questionnaires. The data was analyzed to identify environmental factors that influence subject comfort and behavioral change; and to discover the interrelationship among combinations of environmental factors that impact occupants of open offices.