@article{ref1,
title="Heat loss is impaired in older men on the day following prolonged work in the heat",
journal="Medicine and science in sports and exercise",
year="2018",
author="Notley, Sean R. and Meade, Robert D. and DʼSouza, Andrew W. and Friesen, Brian J. and Kenny, Glen P.",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="PURPOSE: Prolonged work in the heat may exacerbate the rise in core temperature on the next work day, especially in older workers who display impairments in whole-body heat loss that increase body heat storage and core temperature relative to young adults during heat stress. We therefore evaluated whether whole-body heat loss in older adults was impaired on the day following prolonged work in the heat. <br><br>METHODS: Whole-body heat exchange and heat storage were assessed in nine older (53-64 years) males during three, 30-min bouts of semi-recumbent cycling at fixed rates of metabolic heat production (150 (Ex1), 200 (Ex2), 250 Wm (Ex3)), each separated by 15-min recovery, in hot-dry conditions (40°C, 20% relative humidity), immediately prior to (Day 1), and on the day following (Day 2), a prolonged, work simulation (~7.5 h) involving moderate-intensity intermittent exercise in hot-dry conditions (38°C, 34% relative humidity). Total heat loss (evaporative ± dry heat exchange) and metabolic heat production were measured using direct and indirect calorimetry, respectively. Body heat storage was quantified as the temporal summation of heat production and loss. <br><br>RESULTS: Total heat loss (mean±SD) during Ex1 did not differ between Day 1 and 2 (151±15 and 147±14 Wm, respectively; P=0.27), but was attenuated on Day 2 during Ex2 (181±15 Wm) and Ex3 (218±16 Wm) relative to Day 1 (192±14 and 230±19 Wm, respectively; both P<0.01). Consequently, body heat storage throughout the protocol on Day 2 (276±114 kJ) was 31% greater than on Day 1 (191±87 kJ; P<0.01). <br><br>CONCLUSION: Prolonged work in the heat causes next-day impairments in whole-body heat loss, which exacerbate heat storage and may elevate the risk of heat-injury on the following day in older workers.<p /> <p>Language: en</p>",
language="en",
issn="0195-9131",
doi="10.1249/MSS.0000000000001643",
url="http://dx.doi.org/10.1249/MSS.0000000000001643"
}