Tolerable range of abdomen and waist skin temperature for heating-capable smart garments

Abstract

Purpose This study aims to provide information on how to monitor the temperature setting of a heating device in order to implement a heating unit successfully in the smart clothing by observing voluntary heating behavior of wearers.Design/methodology/approach Subjects wearing base layers and additional clothing were asked to turn on and off the switch when wanted in the cold environmental chamber. Tolerable range of skin temperature (TST) depending on the location of body was obtained by observing the temperature at the time when the heating device was turned on and off during a rest–running–rest protocol.Findings The TST was 32.8–49.4 °C and decreased to 31.3–37.6 °C around abdomen and back waist, respectively. Changes in the wearers' voluntary control behavior were observed depending on the individual's level of cold-sensitivity and activity level of rest and running. TST was 35.8–49.4 °C (Rest 1: rest before exercise), 40.0–42.0 °C (Running) and 35.3–43.2 °C (Rest 2: rest after exercise) for cold-sensitive group, whereas it was 32.8–36.2 °C (Running) and 34.4–45.7 °C (Rest 2: rest after exercise) for cold-insensitive group.Originality/value In this study, results with detailed body locations and wearer's thermal sensitivity provide practical references for the implementation of a heating device to the comfortable multilayered smart clothing.

The effectiveness of e-textiles in providing thermal comfort: A systematic review and meta-analysis

“…A preliminary review of the literature has been carried out into trials seeking to evaluate the efficacy of heating e-textiles in cold environments. [4][5][6][7][8][9][10][14][15][16][17][18] Relevant keywords related to heating, textile, and cold environments were identified and preliminary results showed that the common body regions heated by thermal e-textiles are: (a) torso, (b) feet/toes, and (c) more than two regions. To examine thermal wear performance, researchers generally had an experimental group (HEAT) placed in a cold environment and a control group (CON) situated in a thermo-neutral or in a cold environment but wearing unheated clothing.…”

“…In terms of TS and CS, the subjective evaluation would often be assessed by perception ratings from the responders. 4,[7][8][9][10]15,16 Age group, gender, thermal sensitivity, and the type of heating e-textile, i.e. different body region being heated, may be considered as moderators.…”

“…Finally, eight studies met the inclusion criteria and all were RCTs (87.5%), 5,[7][8][9][10]15,16 except one (12.5%). 4 The eight relevant studies were conducted between 2016 to 2021 except for one from 2009. The studies investigated the heating performance on the body surface in different areas such as (a) feet and toes; [7][8][9][10]16 (b) feet, buttocks and shoulders; 15 (c) upper torso 4,5 by different interventions, i.e.…”

“…4 The eight relevant studies were conducted between 2016 to 2021 except for one from 2009. The studies investigated the heating performance on the body surface in different areas such as (a) feet and toes; [7][8][9][10]16 (b) feet, buttocks and shoulders; 15 (c) upper torso 4,5 by different interventions, i.e. specified e-textiles categorized in heating clothes/pads (HCP), 15 heating sleeping bag/socks/insoles (HSB), [7][8][9][10]16 or heating vest (HV).…”

“…In recent years, applications of heating electronic textiles have expanded from purely personal protection to healthcare and medical usage. 1,2 In academic studies, prototypes discussed include a variety of clothing, [3][4][5] wearables, 6,7 and sleeping bags, [8][9][10] which are aimed at improving blood circulation to achieve thermal comfort during daily activities in cold environments and improving sleep quality. Some of these textiles were developed to provide a foot-heating system to treat certain foot conditions.…”