This dataset is in five tables with data from ecophysiological studies of free-ranging polar bears of the Southern Beaufort Sea subpopulation. They were equipped with high-resolution activity sensors, body temperature loggers, and GPS satellite-telemetry collars, to compare physiological state and activity of bears during natural behavior with that experienced by bears during helicopter recapture events (n = 14 bears). The data include: rectal temperatures for comparison to temperatures recorded by implanted loggers, levels of blood biochemical markers (n = 50 bears) related to elevated body temperature and stress for testing whether these markers were influenced by the duration of helicopter operations, ambient temperature, and dose of the immobilization drug.