#0145 Mitigation of heat strain by wearing a long-sleeve fan-attached jacket in a hot or humid environment
Feeling the Heat: Fan-Fitted Jackets Helps Combat Heat Strain
Global warming has increased the earth’s surface temperature considerably, leading to a spike in heat-related illnesses among workers. As a result, deaths related to heat strain has become a major occupational health concern globally. In the past decade, Japan has witnessed a rise in the average number of heat-related illnesses and related deaths among workers. A popular solution to reduce heat stress is fan-attached jackets (FAJs), thin long-sleeved jackets, attached with two small fans near the waist. However, the efficacy of FAJs in lowering the human body temperature under ordinary physical work conditions has not been evaluated.
To this end, researchers from the University of Occupational and Environmental Health in Japan assessed the efficiency of FAJs during physical exertion under extremely hot and/or humid environments.
In their study, they recruited nine healthy Japanese men, each of whom underwent four experiments, each conducted after a gap of minimum 72 hours. Each experiment consisted of a 15-minute rest session, followed by a 60-minute exercise session, and a final 15-minute rest session. During the 60-minute sessions, the participants exercised on a bicycle ergometer, either in a hot-dry (40°C and 30% relative humidity) or a warm-humid (30°C and 85% relative humidity) environment. The assessment was conducted twice for each environment, once when the participants wore an ordinary cotton jacket (control) and once while wearing the FAJ that circulated air at a rate of 12L/s.
The research team continuously monitored the participants’ core body temperatures (rectal, esophageal, ear), skin temperatures, heart rate and sweat volumes indicated by the % weight change.
They found that FAJs markedly reduced the increase in core body temperatures, skin temperatures, heart rates, and % weight change during physical exercise under both hot-dry and warm-humid conditions. Further, they confirmed that FAJs successfully provided cooling effects by reducing the spikes in sweat volume under hot-dry conditions.
This study is the first to confirm that wearing long-sleeved FAJs during physically demanding work helps to reduce heat stress even when the surrounding temperatures are higher than skin temperatures. These findings could pave the way for further investigations into applicability of FAJs under varied work environment conditions and, hopefully, mitigate heat strain among manual laborers.
Link to original journal article:
https://academic.oup.com/joh/article/64/1/e12323/7249380
Title of the paper:
Mitigation of heat strain by wearing a long-sleeve fan-attached jacket in a hot or humid environment
Authors:
Kimiyo Mori, Chikage Nagano, Kimie Fukuzawa, Natsuko Hoshuyama, Riho Tanaka, Kento Nishi, Kahori Hashimoto, Seichi Horie
