Evaluating the usability of a commercial cooling vest in the Hong Kong industries

Abstract

Objective. The provision of appropriate personal cooling vests is recognized as an effective measure to combat heat stress. However, personal cooling vests are not widely implemented in the Hong Kong industries. The current study aims to evaluate the usability of a hybrid cooling vest that is associated with the success of its application in industrial settings. Methods. A self-administrated questionnaire focusing on 10 subjective attributes of cooling effect, ergonomic design and usability of a hybrid cooling vest was administered with 232 occupational workers in the construction, horticultural and cleaning, airport apron services and kitchen and catering industries. Results. A structural equation model estimated by analysis of moment structures was constructed to evaluate the usability of the cooling vest, as influenced by cooling effect and ergonomic design. Results showed that cooling effect (path coefficient = 0.69, p < 0.001) and ergonomic design (path coefficient = 0.55, p < 0.001) significantly affect the usability of the cooling vest. Conclusions. The structural equation model is feasible to examine the complex nature of the structural relationships among the subjective perceptions of personal cooling vests. The empirical findings furnish sound evidence for further optimization of the hybrid cooling vest in terms of cooling effect and ergonomic design for occupational workers.

Keywords:

• cooling effect
• ergonomic design
• occupational workers
• structural equation model

Acknowledgements

The authors wish to acknowledge the contributions of Prof. F.K.W. Wong, Dr Y.P. Guo and Dr W. Yi. In particular, the participation of volunteers in this study is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Perceived effectiveness of protection from heat stroke refers to a subjective sensation of workers who consider that use of a hybrid cooling vest would be an effective measure to reduce the frequency of heat-related symptoms (e.g., dizziness, muscle cramps, vomiting, fainting, lightheadedness).

2. The number of cooling vests of small, middle and large size was 298, 731 and 446, respectively.

3. The sample size is determined by the equation , where n is the required sample size, N = 1475 is the number of cooling vests distributed under the Scheme, P = 0.5 is the estimated variance in population, A = 7% is the precision desired, Z = 1.96 for confidence level at 95% and R = 0.90 is the estimated response rate. Thus, n = 214. Similarly, the sample size in each industry was determined by the same method. In fact, more than 230 workers were recruited for the questionnaire survey.

Additional information

Funding

This project is jointly funded by the Occupational Safety and Health Council [OSHC Research Grant No. CM/4R/2011-01]; the Research Grants Council of the Hong Kong Special Administrative Region, China [RGC Project No. PolyU5107/11E and PolyU5105/13E]; the Natural Science Research Project for Universities and Colleges in Jiangsu Province [No. 15KJB620004].