Evaluation of a carbon dioxide personal cooling device for workers in hot environments.
This study tested the effectiveness of a carbon dioxide cooling device in reducing heat strain for workers in a hot and humid environment. Ten participants completed two trials in an environment of 30 degrees C WBGT (75% relative humidity) with a novel liquid carbon dioxide cooling shirt (CC) or no cooling (NC) in a randomized order. Mean time-weighted workload for each individual equaled 465 W (400 Kcals. h(-1)). In the CC condition, the work time was significantly increased by 32% (97 +/- 36 min) compared with NC (74 +/- 26 min) (p < 0.05). There was no significant difference in mean skin temperature over the trials. Rectal temperature (T(re)) was significantly different after 50 min (p < 0.05). Mean heart rate, the delta T(re) increase rate, and heat storage at 55 min (last point with n = 8) were significantly lower in CC (p < 0.05). Overall heat storage was 54 +/- 41 W and 72 +/- 40 W for CC and NC, respectively (p < 0.05). Participants also indicated favorable subjective responses for CC vs. NC (p < 0.05). These findings suggest that this novel cooling device would effectively attenuate heat strain and increase work productivity for personnel working in a hot and humid environment. Practical aspects of use such as cost, convenience, weight, cooling duration, and rise in ambient CO(2) concentration in confined spaces must also be considered.
Zhang
Yang
Y
Human Performance Laboratory, The University of Alabama, Tuscaloosa, Alabama, USA. yzhang68@bama.ua.edu
Bishop
Phillip A
PA
Green
James Matthew
JM
Richardson
Mark T
MT
Schumacker
Randall E
RE
D000328:Adult; D001831:Body Temperature; D002245:Carbon Dioxide; D004867:Equipment Design; D006339:Heart Rate; D018882:Heat Stress Disorders / Q000517:prevention & control*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D005082:Physical Exertion; D011481:Protective Clothing; D012881:Skin Temperature; D014481:United States
D002245:Carbon Dioxide