Influence of age, geographical region, and work unit on heat strain symptoms: a cross-sectional survey of electrical utility workers

Abstract

This study assessed self-reported heat strain symptoms in workers of a state wide electrical utility distributor to determine risk differences between age groups, geographical work regions and work units. Out of a total 3,250 workers, 918 (∼28%) outdoor staff completed an online survey, which assessed the frequency of self-reported heat strain symptoms in the work and post-work settings, factors contributing to symptoms and symptom management. Heat strain symptoms were grouped into chronic low-grade cases and isolated high-grade cases based on the severity and frequency of symptoms. The risk (likelihood) of an employee being classified as either a chronic low-grade or isolated high-grade case was calculated and compared to the mean risk of all categories to determine risk difference, expressed as −1.00 to 1.00. For chronic low-grade cases, the 41–50 years age group had significantly increased risk (+0.08, p < 0.05) while the over 60 years age group had significantly decreased risk (-0.14, p < 0.05). Two of the three regions (p < 0.01) and three of the nine work units also demonstrated risk differences (p < 0.01) for chronic low-grade cases. Work units were the sole grouping to demonstrate risk difference for isolated high-risk cases. Work units with greater exposure to heat and higher requirement for protective clothing, such as Underground (+0.19, p < 0.05), Overhead – Predominantly Live Line (+0.18, p < 0.01), and Overhead – Distribution and Transmission (+0.11, p < 0.05) were at greater risk of reporting heat stress symptoms. This study demonstrates that the pattern of self-reported chronic low-grade heat strain cases differs to isolated high-grade cases within the electrical utility industry. Age, geographical location, and work unit independently alter the risk of chronic low-grade heat strain, while the risk of isolated high-grade heat strain was only related to work unit. These outcomes support implementation of a flexible and targeted approach to heat stress management in large and diverse organizations in which employees are routinely exposed to heat.

Keywords:

• Environmental risk factors
• self-reported symptoms
• work units

Acknowledgments

Gratitude is expressed to Energy Queensland for supporting this research. Appreciation is expressed to Yvonne Searle, Kevin Hore, and Chris Hubbard for their feedback on the manuscript and to Erin Lewis for the graphic design of Figure 1.

Conflicts of interest

The lead author is an employee of Energy Queensland. The second author is a consultant of Energy Queensland.