A control and measurement system was developed for studying physiological responses of poultry to thermal challenges and means of heat stress relief. The system features automatic control of air temperature and relative humidity (RH); manual setting of air velocity [ ± 0.1 m·s -1 ( ± 20 ft·min -1 )]; and continuous recording of surface and core body temperatures of the animal. The target thermal conditions in the animal occupied zone were achieved inside a wind tunnel [0 to 1.5 m·s -1 (0 to 300 ft·min -1 )] that was situated inside an environment-controlled room and re-circulated the room air. Target air temperature [ ± 0.2 ° C ( ± 0.36 ° F)] and RH ( ± 2%) were achieved by controlling the auxiliary heaters and humidifiers in two stages via a programmable measurement and control module and its peripherals. Animal surface temperatures were time-recorded with an infrared thermal imager [0.06 ° C (0.1 ° F) sensitivity]. Core body temperatures [ ± 0.1 ° C (0.18 ° F)] were collected with a surgery-free telemetric sensing unit that output the data to a PC. Moreover, a surveillance video system was used to monitor and archive animal behavior. The system has been used to quantify the responses of laying hens to various thermally challenging conditions and the efficacy of intermittent partial surface wetting in alleviating bird heat stress under these conditions.