Thermal perception and skin temperature in different transient thermal environments in summer

The effects of air temperature up-step and down-step changes within one test which includes one high-level heat exposure stage and two low temperature stages on subjects' thermal perceptions and skin temperatures were studied. The air temperature of the high-level heat exposure stage was 37 degrees C while the low-level temperatures were 22/26/32 degrees C, thus developing large (C15: 22 degrees C-37 degrees C-22 degrees C), medium (C11: 26 degrees C-37 degrees C-26 degrees C) and small (C5: 32 degrees C-37 degrees C-32 degrees C) step-change conditions. Twenty four healthy subjects were recruited with skin temperatures of seven local body parts sampled. In addition, self reported symptoms and thermal perceptions including thermal sensation, comfort and acceptability were investigated. Results show asymmetry in overall and local thermal sensation with overall and local ATSV after down-steps in C5 and C15 being significantly larger than their counterparts after up-steps. The most sensitive parts are back, arm and leg. Besides, overall thermal sensation change is more intensive than that of any of other local thermal sensations. In the large step-change condition C15, instep temperature contributed most to the fact that more than 45 min was needed for mean skin temperature to achieve steady after down-step. (C) 2016 Elsevier B.V. All rights reserved.