Open AccessMitigation of heat strain by wearing a long‐sleeve fan‐attached jacket in a hot or humid environment
Author(s) -
Mori Kimiyo,
Nagano Chikage,
Fukuzawa Kimie,
Hoshuyama Natsuko,
Tanaka Riho,
Nishi Kento,
Hashimoto Kahori,
Horie Seichi
Publication year - 2022
Publication title -
journal of occupational health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 59
ISSN - 1348-9585
DOI - 10.1002/1348-9585.12323
Subject(s) - strain (injury) , extreme heat , heat stress , environmental science , structural engineering , materials science , composite material , medicine , engineering , geology , atmospheric sciences , physical therapy , climate change , oceanography
Objectives This study examined whether a fan‐attached jacket (FAJ) may mitigate the heat strain in hot or humid environment. Methods Nine healthy men engaged in 60‐min sessions on a bicycle ergometer (4 metabolic equivalents [METs] workload) in hot‐dry (40°C and 30% relative humidity) and warm‐humid (30°C and 85% relative humidity) environments. Both are equivalent to an approximately 29°C wet‐bulb globe temperature. The experiment was repeated—once wearing an ordinal jacket (control condition) and once wearing a long‐sleeve FAJ that transfers ambient air at a flow rate of 12 L/s (FAJ condition)—in both environments. Results Increases in core temperatures in hot‐dry environment were not statistically different between control and FAJ; however, that in the warm‐humid environment were significantly different between control and FAJ (0.96 ± 0.10°C and 0.71 ± 0.11°C in rectal temperature, P < .0001; and 0.94 ± 0.09°C and 0.61 ± 0.09°C in esophageal temperature, P < .0001). Changes in heart rate were different between control and FAJ in both environments (62 ± 3 bpm and 47 ± 7 bpm, P < .0001 in hot‐dry environment; and 61 ± 3 bpm and 46 ± 5 bpm, P < .0001 in the warm‐humid environment) and decrease of %weight change was different in hot‐dry environment (1.59 ± 0.12% and 1.25 ± 0.05%, P = .0039), but not in the warm‐humid environment. Conclusions Wearing a FAJ may mitigate heat strain both in hot or humid environments.