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Abstract
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Background. Environmental conditions of Australia's Northern Territory are seasonally conducive to excessive body heat storage by outdoor workers. For electrical utility workers that periodically work at height, in confined space and in proximity to live power sources, the impact of the climate may be considered a hazardous condition. Therefore, this study examined the physiological and fluid balance responses of 20 power network workers (31.5 yrs; 86.0 kg; 1.71 m; BMI 29.5) throughout work shifts in the Northern and Southern regions of the Northern Territory, Australia.
METHODS. Twenty male heat acclimatized power network workers provided written informed consent to be monitored during maintenance of electrical infrastructure that included replacing power pole components, transformer and substation repairs in the Northern (n = 13) and Southern regions (n = 7) of the Northern Territory (mean wet-bulb globe temperatures of 32.0°C and 28.7°C, respectively). An ingestible telemetry pill provided measurement of gastrointestinal temperature (Tgi), that when combined with heart rate values, provided physiological strain index (PSI). Urine specific gravity, sweat rate and dehydration were also determined.
RESULTS. The Tgi values of this study were within the ISO9886 limit for monitored, heat acclimatised workers, with a peak of 38.4°C. Mean PSI was 2.6, which represents overall low strain, with periods of moderate strain. Urinary analysis indicated that workers were dehydrated prior to and following the work shift, however the mean sweat rate of 0.44 L.h(-1) was matched by fluid consumption of 0.42 L.h(-1) to limit body mass loss to 0.1% during the shift.
CONCLUSIONS. This study demonstrates that heat acclimatized electrical utility workers adhere to ISO9886 requirementswhen undertake self paced activity in hot conditions. While dehydration was evident, relatively low sweat rates were matched by fluid consumption to limit body mass loss during the work shift. Further examination of physiological responses during scenarios that prevent pacing of effort in the heat are warranted.
Language: en |