The effects of facial fanning on thermal comfort sensation during hyperthermia

Abstract

We studied how facial fanning during hyperthermia improves the thermal comfort sensation. Experiments were carried out on ten male subjects. They were immersed in hot water at 40 degrees C for 45 min. At 20 min and 35 min, fanning (1 m x s(-1)) was applied to their faces for 5 min. Core temperature (Tc) measured as esophageal temperature (Tes) and tympanic temperature (Tty) continued to rise during the immersion, but temporarily decreased during fanning with a delay of 2 or 3 min. Skin temperatures (Ts) on the forehead and cheek continued to increase slightly during immersion, but decreased immediately after the start of fanning. During immersion before face fanning, 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 Tc. The scores of both thermal sensation and thermal comfort were reduced significantly immediately after the start of fanning, and their time courses were different to those of Ts and Tty. These results support previous reports that thermal sensation depends on skin temperature, and that thermal comfort depends on both the skin and core temperatures. Moreover, they indicate that both thermal sensation and comfort ratings are affected by the dynamic responses of the cutaneous thermoreceptors when fanning is applied to the face during hyperthermia.

Influence of Beverage Temperature on Exercise Performance in the Heat: A Systematic Review

“…Heart rate was five beats/min lower with facial cooling, and both rating of perceived exertion (RPE) and thermal comfort were also lower. Bradycardia, decreased RPE, and improved thermal comfort at rest and during exercise have also been reported in other studies (Armada-daSilva, Woods, & Jones, 2004;Kato et al, 2001;Smith, Stephens, Winchester, & Williamson, 1997). However, in a study by Gisolfi and Copping (1974), the effect of beverage temperature was compared with cold face sponging (using a towel soaked in cold water at 10 °C) during prolonged running.…”

Real-Time Monitoring of Occupants’ Thermal Comfort through Infrared Imaging: A Preliminary Study

“…Except for the respiration, the rest of the heat exchange mechanisms have a direct impact on the skin temperature [8]. For this reason, much research in the literature identified the skin temperature as an important factor in the assessment of the occupants' comfort [6,9]. For example, Liu et al [10] observed that the time gradient of skin temperature can predict the thermal sensation in cold environments and the heat loss from skin is well correlated with it.…”

“…Commonly, when the skin temperature is used as a parameter for the human thermal sensation and comfort estimation, thermocouples [9,10,24], infrared cameras or thermometers are used [12,16,19]. However, thermocouples are an invasive approach for an everyday application.…”

Neither Arm nor Face Warming Reduces the Shivering Threshold in Unanesthetized Humans

“…The most likely explanation is that unlike sustained warming, rapid increases in skin temperature provoke powerful dynamic responses. 34 Thermoregulatory response thresholds 35,36 and thermal sensation [37][38][39] depend not only on static temperatures but also on the rate at which temperatures change. For example, rapid changes in skin temperature markedly augment cutaneous contribution to the sweating threshold 35,36 and improve thermal sensation during hyperthermia.…”

“…For example, rapid changes in skin temperature markedly augment cutaneous contribution to the sweating threshold 35,36 and improve thermal sensation during hyperthermia. 38 The magnitude of dynamic thermoregulatory response to facial warming remains unknown but may be even greater than for the skin surface as a whole.Rapid increases in skin temperature ameliorate shivering. [17][18][19] A brief reduction in shivering intensity might well facilitate performing a neurological examination, as proposed by Sweney et al 14 Nonetheless, therapeutic hypothermia must be maintained for hours or days and thus represents a thermal steady state.…”