The impact of global warming on population health is a growing concern. Solar energy workers often work in very hot weather; where OSHA supports that there exist some hazards attempting to the health and safety of the workforce. Among the heat-related effects defined as a consequence of exposures to hot environments are, dehydration, heat exhaustion, heat stroke, and death. In order to ensure the safety of the solar workforce, the present study aims to provide with relevant information that could contribute to the development or improvement of safety procedures.The research paper briefly outlines the relation between sunny environments, heat load, heat-related occupational and safety, natural hazards, and climate change conditions. Followed by the description of the assessment method and safety limits. The assessment of levels of heat stress was based on a

he PSH,1 at present year, counts with a tower of 36 m height, a control room and a field of 29 heliostats. The total of the installed heliostats can be separated in two sizes, as follows: 12 heliostats of 36 m2 (each one having 25 flat mirrors of 1.2 m × 1.2 m); 17 heliostats of 37.44 m2 (each one with 32 flat mirrors of 1.3 m × 0.9 m). The total reflecting-area is close to 1,070 m2. The heliostats installed on the field allow reaching a theoretical solar radiation concentration factor of 25, which corresponds to a thermal power of approximat

exposure limits are determined by the following equations (NIOSH, 2016):(4)ÂRAL[°C-WBGT]=59.9-14.1log10M<math><mrow is="true"><mi mathvariant="normal" is="true">R</mi><mi mathvariant="normal" is="true">A</mi><mi mathvariant="normal" is="true">L</mi><mo stretchy="false" is="true">[</mo><mi is="true">Â</mi><mi is="true">°</mi><mi mathvariant="normal" is="true">C</mi><mo is="true">-</mo><mi mathvariant="normal" is="true">W</mi><mi mathvariant="normal" is="true">B</mi><mi mathvariant="normal" is="true">G</mi><mi mathvariant="normal" is="true">T</mi><mo stretchy="false" is="true">]</mo><mo is="true">=</mo><mn is="true">59.9</mn><mo is="true">-</mo><mn is="true">14.1</mn><mi mathvariant="normal" is="true">l</mi><mi mathvariant="normal" is="true">o</mi><mi mathvariant="normal" is="true">g</mi><mn is="true">10</mn><mi mathvariant="normal" is="true">M</mi></mrow></math>(5)Â

Table 3. WBGT exposed levels in °C at different work intensities and rest/ work periods for an average worker with light clothing.

Table 2. Reference values for WBGT (°C) at corresponding work intensity.

WBGT (°C)Recommendations

The WBGT index, described by the ISO 7243, resides in the value weighting of these environmental factors defined by the dry-bulb temperature (T<math><mrow is="true"><mi mathvariant="normal" is="true">T</mi></mrow></math>), natural wet-bulb (static) temperature (Tnw<math><mrow is="true"><msub is="true"><mi mathvariant="normal" is="true">T</mi><mrow is="true"><mi mathvariant="normal" is="true">n</mi><mi mathvariant="normal" is="true">w</mi></mrow></msub></mrow></math>) and black–globe temperature (Tg<math><mrow is="true"><msub is="true"><mi mathvariant="normal" is="true">T</mi><mi mathvariant="normal" is="true">g</mi></msub></mrow></math>). These variables are used to estimate the WBGT index with solar load (1) and WBGT index without solar load (2) (Blazejczyk et al., 2014, Brauer, 2006, Epstein and Moran, 2006, Kjellstrom et al., 2009a, NIOSH, 2016):(1)WBGTout=0.7Tnw+0.2Tg+0.1T<math><mrow is="true"><msub is="true"><mrow is="true"><mi mathvariant="normal" is="true">W</mi><mi mathvariant="normal" is="true">B</mi><mi mathvariant="normal" is="true">G</mi><mi mathvariant="normal" is="true">T</mi></mrow><mrow is="true"><mi mathvariant="normal" is="true">o</mi><mi mathvariant="normal" is="true">u</mi><mi mathvariant="normal" is="true">t</mi></mrow></msub><mo is="true">=</mo><mn is="true">0.7</mn><msub is="true"><mi mathvariant="normal" is="true">T</mi><mrow is="true"><mi mathvariant="normal" is="true">n</mi><mi mathvariant="normal" is="true">w</mi></mrow></msub><mo is="true">+</mo><mn is="true">0.2</mn><msub is="true"><mi mathvariant="normal" is="true">T</mi><mi mathvariant="normal" is="true">g</mi></msub><mo is="true">+</mo><mn is="true">0.1</mn><mi mathvariant="normal" is="true">T</mi></mrow></math>(2)WBGTin=0.7Tnw+0.3Tg<math><mrow is="true"><msub is="true"><mrow is="true"><mi mathvariant="normal" is="true">W</mi><mi mathvariant="normal" is="true">B</mi><mi mathvariant="normal" is="true">G</mi><mi mathvariant="normal" is="true">T</mi></mrow><mrow is="true"><mi mathvariant="normal" is="true">i</mi><mi mathvariant="normal" is="true">n</mi></mrow></msub><mo is="true">=</mo><mn is="true">0.7</mn><msub is="true"><mi mathvariant="normal" is="true">T</mi><mrow is="true"><mi mathvariant="normal" is="true">n</mi><mi mathvariant="normal" is="true">w</mi></mrow></msub><mo is="true">+</mo><mn is="true">0.3</mn><msub is="true"><mi mathvariant="normal" is="true">T</mi><mi mathvariant="normal" is="true">g</mi></msub></mrow></math>

1.1. Physiological response to heat exposure

The periods of high levels of atmospheric heat could end in a modification of the population lifestyle (Lundgren et al., 2013). There exists the big dilemma between those countries who can adapt fast to environmental changes and some others who cannot (Oncel, 2017). The World Health Organization (WHO) revealed that the effects of climate disturbances will cost 320,000 lives per year by 2020 due to natural disasters, high temperatures and diseases (Mekhilef et al., 2011). With changes in the climate that have impact in human lives, the need for a better understanding is increasingly important (Leon 2008 cited by NIOSH, 2016).High levels of GHG emissions have encouraged countries to develop and implement alternatives resources for power generation (Comodi et al., 2016).According to the 2016 Renewable global Status report (REN21, 2017), the global