The effects of facial fanning on thermal comfort sensation during hyperthermia

We studied how facial fanning during hyperthermia improves the thermal comf ort sensation. Experiments were carried out on ten male subjects. They were immersed in hot water at 40 degreesC for 45 min. At 20 min and 35 min, fan ning (1 m(.)s(-1)) was applied to their faces for 5 min. Core temperature ( T-c) measured as esophageal temperature (T-es) and tympanic temperature (T- ty) continued to rise during the immersion. but temporarily decreased durin g fanning with a delay of 2 or 3 min. Skin temperatures (T-s) on the forehe ad and cheek continued to increase slightly during immersion. but decreased immediately after the start of fanning. During immersion before face fanni ng, the time trend of thermal sensation towards the warm level was similar to that of skin temperature on the face, whereas the time trend of thermal comfort ratings towards the uncomfortable level was similar to that of T-c The scores of both thermal sensation and thermal comfort were reduced signi ficantly immediately after the start of fanning, and their time courses wer e different to those of T-s and T-ty. These results support previous report s that thermal sensation depends on skin temperature. and that thermal comf ort depends on both the skin and core temperatures. Moreover, they indicate that both thermal sensation and comfort ratings are affected by the dynami c responses of the cutaneous thermoreceptors when fanning is applied to the face during hyperthermia.