Forehead skin temperature and thermal sensation during exercise in cool and thermoneutral environments.

BACKGROUND: The influence of forehead and mean skin temperature on thermal sensation during exercise in hot, cool, and thermoneutral environments is unclear. HYPOTHESIS: We hypothesized that forehead temperature, in contrast to other skin sites, would contribute significantly to thermal sensation during exercise in hot, cool, and thermoneutral environments. METHOD: Volunteer males (N = 14) performed 30 min of constant load exercise on a cycle ergometer during which thermal sensation, skin and rectal temperatures, and heart rate were collected. Each subject participated in a control (24 degrees C), hot (40 degrees C), and cool (8 degrees C) condition. RESULTS: Significantly higher mean skin temperatures occurred during exercise in the hot condition (M = 37.22 +/- 0.20 degrees C) compared to exercise in the neutral (M = 33.34 +/- 0.51 degrees C) and cool conditions (M = 27.92 +/- 0.22 degrees C). Forehead skin temperature in the neutral and cool conditions was significantly greater than forearm, hand, thigh, and calf skin temperatures (p < 0.05). In the hot condition, forehead temperature was significantly greater than back, chest, upper arm, and hand skin temperatures (p < 0.05). In contrast to the neutral and hot conditions, forehead skin temperature was significantly associated with thermal sensation during exercise in the cool condition (r consistently > 0.67). CONCLUSIONS: We conclude that forehead skin temperature, in contrast to other skin sites, contributed significantly to thermal sensation during exercise in the cool.