Case Study: Self-pacing reduces the risk of Heat Stress

2014 study of electrical utility workers in the Northern Territory found that self-pacing allowed them to maintain a safe body temperature in hot conditions.

The study – published in the Journal of Occupational and Environmental Hygiene – indicated that communication around pacing of effort and identification of impediments to self-pacing could reduce the risk of workplace heat stress.

The research involved monitoring 20 heat-acclimatised male workers in both northern and southern regions of the Northern Territory during the hottest seasons.

Despite the harsh environmental conditions, workers’ internal temperatures did not exceed the international standard threshold of 38.5°C, which was attributed to their ability to self-pace.

“It is reasonable to expect that regular exposure of the utility workers to hot conditions has enabled pacing strategies to be routinely applied and modified,” according to the study authors.

A workers’ understanding of the tasks required, number of staff, time frame and climate conditions, as well as their personal experience, physical fitness and physiological status, are all influential in self-pacing.

“[It] highlights the importance of communication to provide sufficient detail, facilitating informed pacing effort, a strategy not generally associated with heat stress mitigation.”

The authors recommended that further research into emergency scenarios or time-sensitive operations that inhibit self-pacing was warranted, citing power service interruptions as an example, with workers potentially prioritising the restoration of services over their own health.

“Identifying circumstances that inhibit self-pacing may reveal scenarios likely to induce heat stress when undertaken in the hot conditions.”

Additionally, the study suggested that as workplace accidents are more likely during the hottest time of year, understanding that relationship should be prioritised so as to identify hazardous periods.

In the absence of research in these areas, extra consideration should be given to health monitoring and cooling strategies in such scenarios.

“Managing heat stress is likely to have multiple positive outcomes with reference to lower individual and organisational rates of morbidity, fewer accidents, greater sense of comfort, improved renal health, increased productivity and social wellbeing,” according to the study.


Preventing dehydration:

A second finding of the study was that despite the majority of workers starting and ending their shifts dehydrated, a common problem for as much as 60 per cent of workers, fluid consumption approximately matched sweat loss, with only one employee losing more than the recommended 2 per cent of body mass.

In other words, most weren’t significantly more dehydrated at the end of the shift than when they started, a result that the study authors attributed to adequate access to fluids on-site and a relatively low sweat rate amongst the utility workers.

“Maintenance of this trend… combined with improvements in pre-shift hydration on days when duties may limit access to fluids would limit the detrimental effects of dehydration.”

Given that dehydration increases the likelihood of heat stress, fatigue and heat stroke, staying hydrated at work through pre-shift hydration and other strategies is a crucial element of heat stress management.

The increased likelihood of kidney stones also caused the researchers to add that “workplace education packages therefore should address not only the short-term but also the long-term health implications of inadequate fluid consumption.”

For more information on heat stress and hydration management, download THORZT’s free Heat Stress in the Workplace or Workplace Dehydration guides.



About the author / Melisa Capper