The HEAT-SHIELD project - Perspectives from an inter-sectoral approach to occupational heat stress

Objectives: To provide perspectives from the HEAT-SHIELD project (www.heat-shield.eu): a multinational, inter-sectoral, and cross-disciplinary initiative, incorporating twenty European research institutions, as well as occupational health and industrial partners, on solutions to combat negative health and productivity effects caused by working on a warmer world. Methods: In this invited review, we focus on the theoretical and methodological advancements developed to combat occupational heat stress during the last five years of operation. Results: We outline how we created climate forecast models to incorporate humidity, wind and solar radiation to the traditional temperature-based climate projections, providing the basis for timely, policy-relevant, industry-specific and individualized information. Further, we summarise the industry-specific guidelines we developed regarding technical and biophysical cooling solutions considering effectiveness, cost, sustainability, and the practical implementation potential in outdoor and indoor settings, in addition to field-testing of selected solutions with time-motion analyses and biophysical evaluations. All recommendations were adjusted following feedback from workshops with employers, employees, safety officers, and adjacent stakeholders such as local or national health policy makers. The cross-scientific approach was also used for providing policy-relevant information based on socioeconomic analyses and identification of vulnerable regions considered to be more relevant for political actions than average continental recommendations and interventions. Discussion: From the HEAT-SHIELD experiences developed within European settings, we discuss how this inter-sectoral approach may be adopted or translated into actionable knowledge across continents where workers and societies are affected by escalating environmental temperatures.The study has received funding from the European Union’s Horizon 2020 research and innovation program under the grant agreement No 66878

The Effect of Low Ambient Relative Humidity on Physical Performance and Perceptual Responses during Load Carriage

Introduction: The study evaluated the effect of low ambient relative humidity on physical performance and perceptual responses during load carriage in a hot environment.Methods: Ten heat-unacclimatized male subjects participated in three 130-min trials, during which they walked on a treadmill, carrying a load of ~35 kg, at a speed of 3.2 km.h−1, with an incident wind at the same velocity and ambient temperature at 45°C. Each trial commenced with a 10-min baseline at 20°C and 50% relative humidity (RH), the subjects transferred to a climatic chamber and commenced their simulated hike, comprising two 50-min walks separated by a 20-min rest period. In two, full protective equipment (FP) trials, RH was 10% (partial pressure of water vapor, pH2O = 7.2 mmHg) in one (FP10), and 20% (pH2O = 14.4 mmHg; FP20) in the other. In the control trial, subjects were semi-nude (SN) and carried the equipment in their backpacks; RH was 20%. Measurements included oxygen uptake, ventilation, heart rate, rectal and skin temperatures, heat flux, temperature perception, and thermal comfort.Results: In FP20, four subjects terminated the trial prematurely due to signs of heat exhaustion; there were no such signs in FP10 or SN. Upon completion of the trials, pulmonary ventilation, heart rate, and rectal temperature were lower in FP10 (33 ± 5 l/min; 128 ± 21 bpm; 38.2 ± 0.4°C) and SN (34 ± 4 l/min; 113 ± 18 bpm; 38.1 ± 0.4°C than in FP20 (39 ± 8 l/min; 145 ± 12 bpm; 38.6 ± 0.4°C). Evaporation was significantly greater in the SN compared to FP10 and FP20 trials. FP10 was rated thermally more comfortable than FP20.Conclusion: A lower ambient partial pressure of water vapor, reflected in a lower ambient relative humidity, improved cardiorespiratory, thermoregulatory, and perceptual responses during load carriage

Heat acclimation enhances the cold-induced vasodilation response

Purpose It has been reported that the cold-induced vasodilation (CIVD) response can be trained using either regular local cold stimulation or exercise training. The present study investigated whether repeated exposure to environmental stressors, known to improve aerobic performance (heat and/or hypoxia), could also provide benefit to the CIVD response. Methods Forty male participants undertook three 10-day acclimation protocols including daily exercise training: heat acclimation (HeA; daily exercise training at an ambient temperature, T-a = 35 degrees C), combined heat and hypoxic acclimation (HeA/HypA; daily exercise training at T-a = 35 degrees C, while confined to a simulated altitude of similar to 4000 m) and exercise training in normoxic thermoneutral conditions (NorEx; no environmental stressors). To observe potential effects of the local acclimation on the CIVD response, participants additionally immersed their hand in warm water (35 degrees C) daily during the HeA/HypA and NorEx. Before and after the acclimation protocols, participants completed hand immersions in cold water (8 degrees C) for 30 min, followed by 15-min recovery phases. The temperature was measured in each finger. Results Following the HeA protocol, the average temperature of all five fingers was higher during immersion (from 13.9 +/- 2.4 to 15.5 +/- 2.5 degrees C; p = 0.04) and recovery (from 22.2 +/- 4.0 to 25.9 +/- 4.9 degrees C; p = 0.02). The HeA/HypA and NorEx protocols did not enhance the CIVD response. Conclusion Whole-body heat acclimation increased the finger vasodilatory response during cold-water immersion, and enhanced the rewarming rate of the hand, thus potentially contributing to improved local cold tolerance. Daily hand immersion in warm water for 10 days during HeA/Hyp and NorEx, did not contribute to any changes in the CIVD response

Effect of a Simulated Heat Wave on Physiological Strain and Labour Productivity

Background: The aim of the study was to investigate the effect of a simulated heat-wave on the labour productivity and physiological strain experienced by workers. Methods: Seven males were confined for ten days in controlled ambient conditions. A familiarisation day was followed by three (pre, during, and post-heat-wave) 3-day periods. During each day volunteers participated in a simulated work-shift incorporating two physical activity sessions each followed by a session of assembly line task. Conditions were hot (work: 35.4 °C; rest: 26.3 °C) during, and temperate (work: 25.4 °C; rest: 22.3 °C) pre and post the simulated heat-wave. Physiological, biological, behavioural, and subjective data were collected throughout the study. Results: The simulated heat-wave undermined human capacity for work by increasing the number of mistakes committed, time spent on unplanned breaks, and the physiological strain experienced by the participants. Early adaptations were able to mitigate the observed implications on the second and third days of the heat-wave, as well as impacting positively on the post-heat-wave period. Conclusions: Here, we show for first time that a controlled simulated heat-wave increases workers’ physiological strain and reduces labour productivity on the first day, but it promotes adaptations mitigating the observed implications during the subsequent days

The HEAT-SHIELD project - Perspectives from an inter-sectoral approach to occupational heat stress

OBJECTIVES: To provide perspectives from the HEAT-SHIELD project (www.heat-shield.eu): a multi-national, inter-sectoral, and cross-disciplinary initiative, incorporating twenty European research institutions, as well as occupational health and industrial partners, on solutions to combat negative health and productivity effects caused by working on a warmer world.METHODS: In this invited review, we focus on the theoretical and methodological advancements developed to combat occupational heat stress during the last five years of operation.RESULTS: We outline how we created climate forecast models to incorporate humidity, wind and solar radiation to the traditional temperature-based climate projections, providing the basis for timely, policy-relevant, industry-specific and individualized information. Further, we summarise the industry-specific guidelines we developed regarding technical and biophysical cooling solutions considering effectiveness, cost, sustainability, and the practical implementation potential in outdoor and indoor settings, in addition to field-testing of selected solutions with time-motion analyses and biophysical evaluations. All recommendations were adjusted following feedback from workshops with employers, employees, safety officers, and adjacent stakeholders such as local or national health policy makers. The cross-scientific approach was also used for providing policy-relevant information based on socioeconomic analyses and identification of vulnerable regions considered to be more relevant for political actions than average continental recommendations and interventions.DISCUSSION: From the HEAT-SHIELD experiences developed within European settings, we discuss how this inter-sectoral approach may be adopted or translated into actionable knowledge across continents where workers and societies are affected by escalating environmental temperatures.</p

The HEAT-SHIELD project – perspectives from an inter-sectoral approach to occupational heat stress

Occupational heat stress (OH-Stress) is a major societal challenge associated with climate change, as intensified thermal stress directly impacts worker-health and reduces productivity in key industries, causing serious socioeconomic ramifications. This paper was invited to provide perspectives from the HEAT-SHIELD project: a multi-national, inter-sectoral, and cross-disciplinary initiative, incorporating twenty European research institutions, as well as occupational health and industrial partners, dedicated to reducing health and productivity impairments associated with working in a warming world (see www.heat-shield.eu for further information). This invited review will primarily focus on the methodological advancements we developed allowing climate forecast models to incorporate humidity, wind and solar radiation to the traditional temperature-based climate projections, providing the basis for timely, policy-relevant, industry-specific and individualized information. Further, we provide an overview of the industry-specific guidelines we developed regarding technical and biophysical cooling solutions considering effectiveness, cost and the practical implementation potential in outdoor and indoor settings, in addition to field-testing of selected solutions with time-motion analyses and bio-physical evaluations. All recommendations were adjusted following feedback from workshops with employers, employees and adjacent stakeholders such as local or national health policy makers. The cross-scientific approach was also used for providing policy-relevant information based on socio-economic analyses and identification of vulnerable regions considered to be more relevant for political actions than average continental calculations. From the HEAT-SHIELD experiences developed within European settings, we discuss how this inter-sectoral approach may be adopted or translated into actionable knowledge across continents where workers and societies are affected by escalating environmental temperatures