Regional differences in temperature sensation and thermal comfort in humans

Abstract

Sensations evoked by thermal stimulation (temperature-related sensations) can be divided into two categories, "temperature sensation" and "thermal comfort." Although several studies have investigated regional differences in temperature sensation, less is known about the sensitivity differences in thermal comfort for the various body regions. In the present study, we examined regional differences in temperature-related sensations with special attention to thermal comfort. Healthy male subjects sitting in an environment of mild heat or cold were locally cooled or warmed with water-perfused stimulators. Areas stimulated were the face, chest, abdomen, and thigh. Temperature sensation and thermal comfort of the stimulated areas were reported by the subjects, as was whole body thermal comfort. During mild heat exposure, facial cooling was most comfortable and facial warming was most uncomfortable. On the other hand, during mild cold exposure, neither warming nor cooling of the face had a major effect. The chest and abdomen had characteristics opposite to those of the face. Local warming of the chest and abdomen did produce a strong comfort sensation during whole body cold exposure. The thermal comfort seen in this study suggests that if given the chance, humans would preferentially cool the head in the heat, and they would maintain the warmth of the trunk areas in the cold. The qualitative differences seen in thermal comfort for the various areas cannot be explained solely by the density or properties of the peripheral thermal receptors and thus must reflect processing mechanisms in the central nervous system.

Thermal sensitivity to warmth during rest and exercise: a sex comparison

“…Gender differences in thermoregulatory responses exist, particularly in response to heat stress (Cunningham et al 1978;Davies 1979;Havenith 1997;Havenith 2001a:b;Havenith et al 2008;Smith and Havenith 2012) but thermal sensitivity research is generally limited to male participants (Arens et al 2005;Cotter and Taylor, 2005;Nakamura et al 2008;Ouzzahra et al 2012). The present study compared male and female thermal sensation to a 40°C stimulus and overall (mean of rest and exercise), females scored a significantly warmer thermal sensation than males (4.7 ± 1.8 vs 3.6 ± 2.2, p<0.05, respectively).…”

“…A large body of literature indicates a variety of gender linked differences in physiological responses to cold and heat exposure (Cunningham et al 1978;Davies, 1979;Fournet et al 2013;Havenith, 1997;Havenith 2001a;Havenith et al 2008;Hensel, 1973;Havenith, 2011, 2012) yet research on thermal sensitivity tends to be limited to male participants (Nakamura et al, 2008;Ouzzahra et al 2012;Stevens et al, 1974). Females have been shown to be more sensitive than males to a variety of stimuli (Fillingim et al 1998;Otto and Doygher, 1985;Velle, 1987), yet there is a gap in the literature surrounding gender differences in innocuous thermal sensitivity.…”

“…They determined regional differences in the following order of high to low sensitivity: forehead, cheek, chest, abdomen, shoulder, back, forearm, upper arm, thigh and calf. Despite a large number of receptors detected in the hands and feet (Strughold and Porz, 1931;Rein, 1935, both cited in Parsons, 2003Jasper and Penfield, 1954), higher sensitivity has been reported by numerous researchers in the head and torso region (Arens et al 2005a;Nadel et al 1973;Nakamura et al 2008;Stevens et al 1974). Nakamura et al (2008 speculated that the central nervous system assigns weighing factors for each body segment and that this is what determines the regional differences in sensitivity rather than receptor density.…”

“…Nakamura et al (2008 speculated that the central nervous system assigns weighing factors for each body segment and that this is what determines the regional differences in sensitivity rather than receptor density. The weighing factors are related to basic functioning of temperature regulation which must maintain the temperature of the torso and head due to the vital organs located there (Nakamura et al 2008). …”

The Influence of Selective Cooling of the Body Surface on the Improvement of Physiological Indicators of the Body and the Subjective Assessment of Thermal Comfort During Activities Carried Out in the Hot Climatic Zone

“…limbs). In one of the experiments carried out, Nakamura et al (2008) observed that in heat conditions, local cooling of the face surface has a positive eff ect on thermal comfort for the whole body. Therefore, selective cooling of the head area is an external interference in the mechanisms of thermoregulation, it positively aff ects not only the feeling of comfort for the whole body, but also it also contributes to the reduction of the degree of nuisance of the performed activities.…”