Current World Environment

Introduction

Outdoor workers are the front-liners who are exposed to various physical, biological, chemical, ergonomic and psychological occupational hazards. Among these hazards, one of the most prominent ones are theenvironmental stresses and severe climatic conditions. They are mostly exposed for a longer period to high levels of heat and other stresses like UV radiation, atmospheric pollutants, and urban heat island (UHI) effect.¹This chronic exposure canproduce severe as well as frequent known occupational health hazards.^2,3 In past studies, it has been reported that the rise in outdoor temperature can result in health issues foroutdoor workers. The frequent, severe, and long-term exposure to UVradiations causes severe health effects in workers;such as eye problems, skin cancer, and immune dysfunction.^1,4,5,6,7In addition to these health effects, heat stroke, heat syncope, heat rash, heat exhaustion, and rhabdomyolysis are some of the most common heat related health issues which occur due to long-term exposure to frequent and intense heat or high temperature. Exposure to high temperature can also affect the focusof workers on their work, andthis result in higher risk of injury and lapse in their safety. Furthermore, due to prevalent global climatic changes and Urban Heat Island (UHI), the levels of atmospheric pollutants, particularly ground level ozone, are increased. The exposure of outdoor workers to such air pollutants has chronic health effects (like allergic reactions and various respiratory problems). ^8,9,10,11,12

Heat exposure and climatic effects cause objective and subjective health related symptoms like heat cramps, heat rash, heat edema, synope etc.¹³These are in line with hypotheses that the exposure to heat increases the risk of occupational ill health, accidents, and injuries. It is reported in Taiwan and Thailand that temporary workers suffered from intense heat strain due to working in hot and physically demanding works at the construction sites along with hot living conditions in sites near residences.¹⁴According to Campbell (2018) heat waves have caused an increase in the hospitalization rate due to upsurge in the rate of cardiovascular diseases during the high temperature periods in Vietnam and Puerto Rico.¹⁵By improving the living and working conditions of workers at workplace, the heat related issues can be eliminated or minimized.¹⁴ Climate extremesare some of the most evident environmental problems of this century, which are impacting human’s health in one way or another. Along with this, the prevailing situation of air pollution and urban population growth, which according to the United Nations is expected to increase to about 57% in 2050, are exacerbating the situation especially in developing countries.¹⁶ Keeping in mind this scenario, World Health Organization (WHO) has asked the members states to take significant measures to curtail the impacts of climate change associated with human health.¹⁷

Although climate change is one of the most familiar global environmental issues of the present and future, yet its harmful effects on occupational health and safety of human resources (workers and employees)havenot been given much consideration.¹⁸ Owing to the rapid expansion of cities globally, the urban island heat effect (UHI) has become an effect of climate change due to human induced activities.¹⁹ Climate change impacts have altered the ambient environment for workers, due to which new hazards have been added to already existing ones in the workplace. As a result, outdoor workers will have to face harsh working conditions; extreme heat, toxic substances, and higher risk of infectious and vector bornediseases.^1,7 In addition to these impacts, there will be risk of damage to infrastructure and ultimately humans like community members, workers, and emergency crew from extreme weather conditions.²⁰ According to International Labor Organization (ILO), fire fighters, farmers, emergency responders, health care staff, transportation workers, and utility workers will be more vulnerable to climate change.²¹

Furthermore, climate change intensifies the health and safety issues and their severity of risk to workers in workplaces. It is anticipated that workers will be more affected by climate change than public as they will be frequently exposed to harsh weather conditions. Exposure to heat and effects of climate change and their severity will be more for outdoor workers (migrant workers, day laborers, or any other who has social or economic problems). This article summarizes the current informationon relevant health effects of climate change, exposure to extreme temperatures on outdoor workers.It also offers various available adaptation plans to reduce the impacts of climate change and to enhance capacities of outdoor workers.  The current study focuses only on tropical developing countries, and the main aim of this studyis to draw the attention on devolving research areas because of their relevance to the effects of extreme heat exposure, health and safety concerns and climate change adaptation actionsof outdoor workers. It encompasses the chances of effects of climate change and exposure to heat that will at the end affect the productivity of outdoor workers. Accordingly, not only direct but also indirect hazards of increasing heat to health and safety of vulnerable groups of outdoor workers, exposure to harmful chemicals, vector borne diseases and infectious arediscussed. Moreover, the principle methodology for compiling this study is the literature search (including research papers, review papers and organizational reports) relevant to the core areas of this study.

This study will aid the policy makers, researchers, decision makers, academicians, and regulators to undertake efficient measures to tackle the adversities of climate change and exposure to heat. Exposure to humid and harsh environment, extreme weather conditions, biological and air pollutants are some of these adversities of climate change on occupational health and safety of workers or occupational hazards.

Figure 1: Climate Change and Occupational Health and Safety, Adopted and Modified from Schulte and Chun, 2009.20 Click here to view Figure

Typical Climate of Tropics, Heat and its Effects

Tropics refer to the regions that lie between tropic of Cancer (23.45 ºN) and tropic of Capricorn (23.45 ºS), different regions have difference in their climate and temperature patterns.²² The areas adjacent to tropical rainforests (like Philippines, Cebu, Mactan etc) have mean temperature of 22 to 28 ºC with high humidity, while areas like Bangladesh adjacent to seasonal tropical forests often reach 40 ºC and even more.²³ Moreover, tropics have dry regions as well, which include the areas adjacent to hot deserts where the temperaturein summer exceeds 40 ºC in the afternoon and drops up to 30 ºC at night or early morning.²² Just like the rest of the world, climate change is occurring in the tropics as well, and the warming of 0.7 to 0.8 ºC has been noted.²⁴ Singapore is an example of this warming, and it is estimated that it may become the warmest place till the next century.²⁴ This rise in temperature has initiated many impacts in the tropics; which include frequent floods, drought, glacial melting, coral bleaching etc.²⁴Moreover, according to fifth report of IPCC, not only the frequency and intensity of heat waves is increasing but also their length of prevalence is increasing, which is an adverse impact of climate change.²⁵ It has been found that these heat waves are influencing the health of populations in tropical regions. In Vietnam, which is located within latitude of 10º-23º N, heat waves have caused an increase in the hospitalization rate due to upsurge in the rate of cardiovascular diseases during the high temperature periods in this country.¹⁵Puerto Rico (located at 18 ºN), which is an island; its population has reported increase in mortality rates due to stroke and cardiovascular diseases during the high temperature periods.¹⁵

Exposure to Heat and Hot Environments at Workplace

Workers exposed to intense heat, hot work environment for extended time, or involved in exhausting physical works might be at risk of heat stress. Some of the most common and adverse effects of heat exposure are heat stroke, heat exhaustion, rhabdomyolysis, andoften death of individual.³Work related exposure to heat also increases the risks of traumatic injury. The increase induration, frequency, and intensity of exposure to heat elevatesthe risk of illness and death.^26,27

Besides outdoor workers, goods deliverymen, utility workers, farm workers, construction workers and all those who have to work on unsuitable outdoor work environment such as lack of ventilation systemare at high risk of various hazards related to heat.²⁸ In general, workers in all those workplaces have inadequate welfare facilities; likeaccess to water, availability of rest area, and cool space are at high level of risk.²⁹The rise in atmospheric temperature due to climate change increases the risk of exposure and their effects on workers of certain toxic chemicals.³⁰ Volatilization of certain chemicals occurs due to rise in temperature, which increases the risk of exposure to these environmental pollutants.It means that the toxicity (ability of a chemical to cause harm) and the mobility of chemical pollutants are increased due to climatic changes.This leads to transportation of airborne particles to remote areas.³¹For instance, the alteration in food webs, melting of ice cover and changes in carbon cycle increase the concentration of PersistentOrganic Pollutants (POPs) in soil, waterand biosphere.³² The high atmospheric humidity and temperature enhances persevere of the chemicals for a longer time in atmosphere.

Extreme Weather Conditions and Air Pollution

Natural disasters or extreme weather events (floods, droughts, landslides, storms, lightning, wildfires etc) are often responsible for injuries, diseases, mental stress, and death of workers at workplace. During and after the disaster, the staff involved in rescue and rehabilitation operations is at risk of exposure to different hazards at the site. Furthermore, acute and chronic health problems like cardiac diseases, pulmonary disorders, and various allergic problems are aggravated by air pollution.^33,34 Moreover, there are some factors that affect the exposure to air pollutants like location of workplace or site, weather conditions, and materials being used at the site. Generally, warmer temperature creates greater chance of air pollutants’exposure (such as particulate matter and ground-level ozone).^35,36,37 Furthermore, workers are presumably affected by increased air pollution during pollen production season. These affected workers include the outdoor workers (such as drivers, firefighters etc.)and the indoor workers inhaling unfiltered air.²

Biological Hazards

Frequent changes in average temperature and rainfall patterns badly affect the spread of pathogens, vectors, plants, and allergens. The overall rise in the temperature due to climate change has been affecting the human health in a number of ways. One of them is the frequent outbreak of epidemics (infectious/contagious diseases). The infectious agents like bacteria, viruses and protozoa along with the vectors like ticks, flies and mosquitoes are influenced by climatic variability. Therefore, the climate change boosts their production and increase the extent of diseases transmission in human beings. There health issues caused by such pathogens can be food borne diseases, water borne diseases (e.g:typhoid), vector borne diseases (e.g: Zika, Dengue, Lyme,Chikungunya etc.), asthma (due to molds and pollens), and health effects caused by poisonous plants (e.g: skin and lungs irritation). Apart from health impacts linked with biological hazards, multiple adverse occupational health disorders are related to pesticides exposure. For instance, organochlorine pesticides can cause chronic bronchitis; insecticides can result in sarcoidosis; and bipyridyl herbicides can develop allergic rhinitis.³⁸ As compared to the indoor workers, outdoor workers are more vulnerable to these effects.

Outdoor Workers Exposure to Heat Stress and Its Health Outcomes

Studies have revealedthat thousands of workers can become ill every year due to exposure to working environments characterized by high temperatures.⁵ Most of the people exposed to high level of heat develop chronic illnesses while others become allergic to heat conditions.⁴Workers tend to perform ineffectively when the working conditions are not favorable. According to Roghanchi and Kocsis (2018), workers perform differently when exposed to diverse conditions. When working in a hot environment, there is a high likelihood of heat increase because of the normal metabolic activities and heat from the sun. Generally, the impact of heat on health ismeasured in terms of mortality or hospital admissions.⁵³Aged workers and those with impaired health are particularly at risk when exposed to heat and elevated temperature due to climate change. Heatstroke isan impact thatcan also occur in physically healthy workers who carry out intensive heavy work in longer exposure to heat due to social and economic problems. The heat related illnesses come from exposure to hot temperatures or prolonged heat. In order to cause cooling effect within human body during prolonged heat exposure, blood rushes and reaches to the surface of the skin. Thus, less blood comes to the brain, muscles, and different organs. This could interfere with both physical strength and mental capacity leading sometimesto risks that may damage the health, and causesdisorderssuch as heat induced rash, stroke and cramps, heat syncope and rhabdomyolysis.

Table 1: Health Issues Related to Heat Stress.

At many outdoor working sites,workers reported that those who experienced heat stress often had to stop working, and the results were fatalin some cases. Therefore, thermal stress isthe major cause of health complications among such workers.⁵The fatalities in thermal stress often increase during summer when the temperatures are extremely high. Since most countries do not have heat stress regulation methods, heat prevention and treatment of symptoms could be an option that could help construction companies to deal with heat stress.⁴⁰ The effects of heat stress on normal body functioning can be measured using the rate of heartbeat, body consumption of oxygen, expenditure of energy, fatigue, and minute ventilation.⁴¹These measurements are brought out via case control studies. There exists strong evidence that heat has physical, psychological, and mental effects on the health of these construction site workers due to exposure to heat stress. Among the effects is the exhaustion and skin burns, lowering of cognitive performance, psychological impacts, loss of productivity, and the buildup of these conditions develop to severe illnesses like skin cancer and thermal stress.^42,43

Heat stroke is a significant heat related health issue, and it should be treated as a prioritizedmedical emergency. The occurrence of heat stroke is caused by the condition when the human body does not effectively dissipate heat and lose the ability to regulate the body temperature.^4,44 The mean body temperature quickly raises, homeostasis mechanism stops working, and the body becomes unable to lower the temperature. At the time of heat stroke, body temperature reaches to 106°F or higher within ten to fifteen minutes. Heat exhaustion mostly leads to heat stroke which occurred after being exposed to high temperatures accompanied by elevated core body temperatures around 100.4°F–102.2°F, and it often is escorted by dehydration.⁴⁴ The normal range of human body temperature is 36.5 to 37.5 ºC, but when exceeding from 40 ºC or 40.5 ºC (equivalent to 104 and 105 ºF respectively) it may leads to heatstroke.¹³ Generally, if environmental temperature is between 40 ºC or 54 ºC (between 105 and 130 ºF), then human beings can experience heat exhaustion. Moreover, if this environmental temperature exceeds 54 ºC (130 ºF), then it leads towards heat stroke.⁴⁵ Heat stroke results in death or permanent disability ifemergency medical treatment is not provided timely. The main signs of heat stroke are slurred speech, hot dry skin, confusion, clumsiness,fainting/unconsciousness, profuse sweating, seizures, and high body temperature.Due to over sweating,body losses enough water and minerals, which causes muscles cramps (that occur in a hot environment or during or after exercise) or spasms called heat cramps. This results inpain and spastic contractions in voluntary muscles (mostly in the arms, legs and torso).

Role of Governments and International Standards

The temperature on the Earth is increasing at an alarming rate, which in future will demandgovernments, employers, and workers to be more prepared for facing the health risk of climate change. It will be a prerequisite to take critical steps to follow adaptation, to manage various health risks of climate change particularly impacts of high temperature. This could be achieved by proper regulatory frameworks like labor-relatedagreements, standards, regulations and rules. The role of international labor standards in the promotion of adaptation to reduce the impact of rising temperature is very helpful around the world. These international standards provide various tools for the management of health-related issues related to extreme heat stress, and to safeguard the decent work conditions in workplaces. The Occupational Safety and Health Convention, 1981 (No. 155), and its associated Recommendation, (No. 164) both consider heat stress as a significant hazard at workplace. The C155 and R164, international labor standards, both provide direction to the states for formulation and execution of national occupational safety and health policy. In addition to other workplace hazards, this policy will specifically address heat stress in accordance with the requirements and consultation of stakeholders, i.e., individuals, employers, and workers’ organizations.

Additionally, according toOccupational Safety and HealthConvention No. 155,prevention of illness, injuries and accidents occurring at the workplace is the responsibility of national occupational safety and health safety polity. The complementary Recommendation No. 164 requires national Occupational Safety and Health policy to include actions taken for regulating physical factors such as humidity, temperature, light and ventilation at the workplace. Moreover, other international labor standards such as the Workers’ Housing Recommendation, 1961 (No. 115), the Protection of Workers’ Health Recommendation, 1953 (No. 97) and the Hygiene Recommendation, 1964 (No. 120) suggest regulations for managing heat stress risk and adaptation efforts by workers’, employers’ and government organizations. Furthermore, Recommendation No. 97 demandsthat employers should carry out all necessary actions to eliminate, reduce, mitigate and prevent all possible hazards and risks at the workplace and provide sufficient and suitable protection to the workers including excessive heat and sudden temperature variations.

Table 2: International Standards for the Management of Health-Related Issues Related to Extreme Heat Stress.

Governments are the main bodies thatare involved in controlling environment that affect the behavior of employers and workers. They also provide guidelines for the different actions to be carried out for the control of adversities of heat stress and climate change on a workplace. A regulatory framework is very necessary to be implemented for these issues. An early alarm system for heat extremes is very important to mitigate such extreme temperature problems.^35,46In developingcountries, the main constraints are financial and technical restrictions. These should have to be considered prior to the development of such a mechanism. It is crucial to promote international cooperation, information sharing and joint action under the umbrella of International Labor Organization (ILO) to attain the overall development of the infrastructure needed to adapt to heat stress.It would help in strengthening resilience and adaptive capacity of workers who are the most vulnerable to heat stress like farm workers.^21,47Social protection instruments can compensate for the loss of income, employment due to environmental hazard at work.Regulatory interventions are required for the promotion of special technologies, advancement in technical standards for infrastructure and strengthening of public employment polices to tackle the problem of migration of workers from rural areas to cities or to facilitate migration due to future impacts of climatic events on vulnerable works group.Sometimes temporary or permanent migration is the only adaptation strategy to mitigate the effects of climate change.

Heat Exposure Mitigation

The laborers, working outdoors or in an open environment that are prone to long-term heat exposure including construction, agricultural workers, road cleaners and municipality, fire fighters, window cleaners, fueling and service station attendants etc. In urban areas with climatic and weather conditions along with air pollution, Urban Heat Island may further aggravate the situation and impactoutdoor working conditions. To adequately address heat stress, it is best to manage this holistically and implement a variety of measures including assessment of the onsite risks and determination of hazards, implementation of suitable effective engineering control measures, devising effective heat stress program for workers effected from heat stress, implementation of mid-day break, working hours, facilities provision regulations during the summer months for outside employees.

A comprehensive risk assessment and acclimatization program, an effective communication system,onsite welfare facilities, provision of appropriate body cooling devices, pre-employment screening and medical clearance canbe considered for outdoor heat exposure managing techniques. Moreover, personal protective gadgets, administrative andengineering measures are always viable options in reducing the impacts of workingoutdoor, especially in extreme summer and extreme winters. Studies have identified that thermal stress is among the leading heat-related illness and prolonged exposure to the sun without breaks hampers the performance and effectiveness of an employee.^5,46Therefore, depending upon work site conditions,shortening of working periods,job rotation, frequent rests, improvement of ventilation, and provision of air conditioning facility can be very effective. Along with this, using sunscreen, light clothes on head, goggles, putting on hats, and construction of movable shades are proven best safety and health practices according to literature.⁴⁸

Climate Change Adaptation

In order to ensure minimization of the impacts of climate change on occupational health and safety (work related illnesses and injuries) of outdoor workers, multiple approaches would be required. Employers’ and employees’ readiness inmitigating the impacts of climate change can not only be evaluated by recognition and anticipation of potential occupational safety and health hazards and climate change, but also their mitigation methods.⁴⁹For example, adaptation and mitigation policies of climate change couldresult in changes in building design and energy consumption which can have positive impacts on health and safety of workers. The scope of occupational health surveillance should be expanded to incorporate health and safety impacts caused by climate change on workers.⁴⁹

Figure 2: Framework of the Centers for Disease Control and Prevention (CDC), Building Resilience against Climate Effects (BRACE), Adopted and modified from Centers for Disease Control and Prevention.39 Click here to view Figure

A holistic method which is adopted to address the possible influence of climate change on health and safety of employees and workers includesintegrated hazard recognition,coordination and response.⁵⁰The vulnerability assessment leading to mitigation action and evaluation can be utilized to reduce occupational health and safety hazards and risks making the workplace environment safe for the workers, according to the “Building Resilience against Climate Effects Framework of the Centers for Disease Control and Prevention”.^49,51

The commitment of the top management, workers’ participation in hazard identification, risk assessment process and taking control measures are some of the main procedures for the management of health and safety. These practices should focus on existing and additional health hazards which arise from climate change. The BRACE framework (an adaptive management approach) can help employers and workers to adapt to the new normal. Following is the list showing employer’s preparedness:

• Allocation of resources for identification of hazards
• Identification of vulnerable groups in workplace
• Ensure the execution of control measures in accordance with policies, procedures, and equipment

Employer readinessconsists of amendments in building safety, scheduling, work operations and interactions and integration with other preparedness;such as involving the fire department in process safety management or launching a communication system to reach workers at home.⁵² National Institute for Occupational Safety and Health (NIOSH) provides recommendations that emergency responders must be protected under any circumstances and facilitates the integration of health monitoring system into incident command structure for long-term monitoring of potential health effects after exposure of emergency-response (The Emergency Responder Health Monitoring and Surveillance Framework).⁴⁴

Conclusion

It is evident that due to intense climatic and weather conditions, severe workplace heat exposuresincrease the rate of incidents and health illnesses indeveloping countries and fast-paced working places. General public’s health is the most addressed research and policy issue till date in climate change research; however, much evidence is also present regarding the influence of climate change on occupational health and safety of employees and laborers in outdoor environments. Workplace heat exposure along with the climatic extremes result in rise in heat related injuries and manual workers,especially in tropical regions. If effective climate adaptation and heat exposure avoidance procedures are taken in the workplace, such effectscan bereduced. Owing to the lack of reporting system of heat-related disorders and the lack of awareness, the possible impacts of workplace heat exposure are miscalculatedglobally.From the studies considered, it is evident that safety and health of outdoor workforce areinfluenced by many factors like socio-demographic variables, policy and regulations, prevailing working conditions, availability and provision of facilities at workplace, and worker’s own attitude.  The workers' attitude, behavior, ideas, perceptions, and beliefs however are proved to be the significant factors in many studies as theyshapeworkers’ orientation towards safety, hazards, and risks. Along with the consideration of procedures for the protection of human resources (employees and workers) from extreme heat exposure because of climate change, the development of appropriate surveillance programsis unavoidable. These may help in suitable occupational heat exposure assessmentand mitigationof the injuries and ill-health effects that occur due to high temperature caused by climate change extremes.

Acknowledgments

This publication was supported by Deanship of Scientific Research (DSR) at King Abdulaziz University. So, the authors, acknowledge with thanks DSR and Department of environmental sciences King Abdulaziz Universityfor their support.

Funding Source

There is no funding or financial support for this research work.

Conflict of Interest

Declare the conflict of interest in the manuscript.

References

1. Schulte PA, Chun H. Climate Change and Occupational Safety and Health: Establishing a Preliminary Framework. J. Occup. Environ. Hyg.2009;6:542–554.
   CrossRef
2. Ahmad I, Balkhyour MA, Abokhashabah TM, IsmailIM, Rehan M. Workplace Safety and Health Conditions and Facilities in Small Industries in Jeddah. Saudi Arabia. Journal of Safety Studies.2017a;3(1):37-52.
   CrossRef
3. Ahmad I, BalkhyourMA, AbokhashabahTM, IsmailIM, RehanM. Occupational Musculoskeletal Disorders among Taxi Industry Workers in Jeddah.Saudi Arabia: Biosciences Biotechnology Research Asia. 2017b;14(2):593-606.
   CrossRef
4. Ahmad I, RehanM, BalkhyourMA, IsmailIM. Assessment of Occupational Health and Safety in Motor Vehicle Repair Workshops in Jeddah. Biosciences Biotechnology Research Asia.2017c;14(3):901-913.
   CrossRef
5. Abokhashabah T, Jamoussi B, Summan AS, Abdelfattah E, Ahmad I.A review of occupational exposure to heat stress, its health effects and controls among construction industry workers: A case of Jeddah, KSA. Int. J. Biosci. 2020;17(1):35-45; doi:10.12692/ijb/17.1.35-45.
   CrossRef
6. Kiefer M, Lincoln J, Schulte P, Jacklistch B. Climate Change and Occupational Health and Safety. NIOSH Science Blog. Centre for Disease Control and Prevention. 2014.
7. Flouris AD, Dinas PC, Ioannou LG, Nybo L, Havenith G, Kenny GP, Kjellstrom T. Workers’ health and productivity under occupational heat strain: A systematic review and meta-analysis. Lancet Planet. Health.2018;2:e521–e531.
   CrossRef
8. Kjellstrom T, Kovats RS, Lloyd SJ, Holt T, Tol RS. The direct impact of climate change on regional labor productivity. Arch. Environ. Occup. Health. 2009;64:217–227.
   CrossRef
9. Nilsson M, Kjellstrom T. Climate change impacts on working people: How to develop prevention policies. Glob. Health Action. 2010;3:1543.
   CrossRef
10. Gubernot DM, Anderson GB, Hunting KL. The Epidemiology of Occupational Heat-Related Morbidity and Mortality in the United States: A Review of the Literature and Assessment of Research Needs in a Changing Climate. Int. J. Biometeorol.2014;58:1779–1788.
    CrossRef
11. Campbell-Lendrum D, Manga L, Bagayoko M, Sommerfeld J.Climate change and vector-borne diseases: What are the implications for public health research and policy? Philos. Trans. R. Soc. B Boil. Sci.2015;370:20130552.
    CrossRef
12. EASAC European Academies’ Science Advisory Council. The Imperative of Climate Action to Protect Human Health in Europe; EASAC Policy Report 28 June 2019; EASAC European Academies’ Science Advisory Council: Halle, Germany, 2019; ISBN 978-3-8047-4011-2.
13. Behera JR, Mohanty N. Heat-related illness in Tropics. IAP Textbook of tropical diseases. 2020:689-696.
14. Behera JR, Mohanty N. Heat-related illness in Tropics. IAP Textbook of tropical diseases. 2020:689-696.
15. Yoopat P, Toicharoen P, Glinsukon T, Vanwonterghem K, Louhevaara V. Ergonomics in practice: physical workload and heat stress in Thailand. Int J Occup Saf Ergon. 2002;8:83–93.
    CrossRef
16. Campbell S, Remenyi TA, White CJ, Johnston FH. Heatwave and health impact research: A global review. Health and place. 2018; 53:210-218.
    CrossRef
17. Moda HM, Minhas A. Impacts of climate change on outdoor workers and their safety: some research priorities. International journal of environmental research and public health. 2019;16(18):3458.
    CrossRef
18. WHO. Heat-Health Action Plans Guidance; WHO Regional Office for Europe: Geneva, Switzerland, 2008.
19. Thomas F, Sabel CE, Morton K, Hiscock R, Depledge MH. Extended impacts of climate change on health and wellbeing. Environ. Sci. Policy.2014;44:271–278.
    CrossRef
20. Naserikia M, Shamsabadi EA, Rafieian M, Filho WL. The Urban Heat Island in an Urban Context: A Case Study of Mashhad, Iran. Int. J. Environ. Res. Public Health. 2019;16:313.
    CrossRef
21. Schulte PA, Chun H. Climate change and occupational safety and health: establishing a preliminary framework. J Occup Environ Hyg.2009;6(9):542-54. PMID: 19551548. doi:10.1080/15459620903066008.
    CrossRef
22. ILO. World Social Protection Report 2017–19: Universal social protection to achieve the Sustainable Development Goals (Geneva). 2018b. World Employment and Social Outlook 2018: Greening with jobs (Geneva).2017.
23. Galvin JFP. The weather and climate of the tropics, Part 1- Setting the scene. Weather. 2007; 63(9):245-251.
    CrossRef
24. Galvin JFP. The weather and climate of the tropics, Part 9- Climate, flora and fauna. Weather. 2009; 64(4):100-107.
    CrossRef
25. Corlett RT. The impacts of climate change in the Tropics. State of the Tropics Report. 2014; 155-160.
26. Intergovernmental Panel on Climate Change, 2013. Climate Change 2013: The physical science basis, contribution of working group 1 to the fifth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge, United Kingdom.
27. Xiang J, Bi P, Pisaniello D, Hansen A. The impact of heatwaves on workers’ health and safety in Adelaide, South Australia. Environ. Res.2014;133:90–95.
    CrossRef
28. Thompson KMA, Coates AM, Incognito AV, Whinton AK. Chronic heat exposure for health and exercise performance - cardiovascular research heats up. J. Physiol. 2017;595(13):4137-4138. doi:10.1113/JP274003.
    CrossRef
29. Gubernot DM, Anderson GB, Hunting KL. The epidemiology of occupational heat exposure in the United States: a review of the literature and assessment of research needs in a changing climate. International Journal of Biometeorology. 2014;58(8):1779-1788.
    CrossRef
30. Kjellstrom T, Freyberg C, Lemke B, Otto M, Briggs D. Estimating population heat exposure and impacts on working people in conjunction with climate change. Int J Biometeorol.2018;62(3):291-306. doi:10.1007/s00484-017-1407-0. PMID: 28766042.
    CrossRef
31. Balbus JM, Boxall AB, Fenske RA, McKone TE, Zeise L. Implications of global climate change for the assessment and management of human health risks of chemicals in the natural environment. Environmental Toxicology and Chemistry. 2013;32:62–78.
    CrossRef
32. Bourbonnais R, Zayed J, Levesque M, Busque MA, Duguay P, Truchon G. Identification of workers exposed concomitantly to heat stress and chemicals. Industrial Health. 2013;51:25–33.
    CrossRef
33. Noyes PD, McElwee MK, Miller HD, Clark BW, Tiem LA, Walcott KC, Erwin DL. The toxicology of climate change: Environmental contaminants in a warming world. Environment International. 2009;35: 971-986.
    CrossRef
34. Gubernot DM, Anderson GB, Hunting KL. The Epidemiology of Occupational Heat-Related Morbidity and Mortality in the United States: A Review of the Literature and Assessment of Research Needs in a Changing Climate. Int. J. Biometeorol.2014;58:1779–1788.
    CrossRef
35. Campbell-Lendrum D, Manga L, Bagayoko M, Sommerfeld J.Climate change and vector-borne diseases: What are the implications for public health research and policy? Philos. Trans. R. Soc. B Boil. Sci.2015;370:20130552.
    CrossRef
36. Bi P, Williams S, Loughnan M, Lloyd G, Hansen A, Kjellstrom T, Dear K, Saniotis A. The effects of extreme heat on human mortality and morbidity in Australia: Implications for public health. Asia Pacific Journal of Public Health.2011;23(2):27–36.
    CrossRef
37. Fiore AM, Naik V, Leibensperger EM. Air quality and climate connections. Journal of the Air and Waste Management Association. 2015;65:645–685.
    CrossRef
38. US Global Change Research Program. The impacts of climate change on human health in the United States: A scientific assessment. Washington, DC. 2016.
39. Ye M, Beach J, Martin JW, Senthilselvan A. Occupational Pesticide Exposures and Respiratory. Health International Journal of Environmental Research and Public Health. 2013; 10:6442-6471.
    CrossRef
40. Kjellstrom T, Briggs D, Freyberg C, Lemke B, Otto M, Hyatt O. Heat, Human Performance, and Occupational Health: A Key Issue for the Assessment of Global Climate Change Impacts. Annu Rev Public Health.2016;37:97-112. PMID: 26989826.DOI: 10.1146/annurev-publhealth-032315-021740.
    CrossRef
41. Yi W, Chan APC. Effects of Heat Stress on Construction Labor Productivity in Hong Kong: A Case Study of Rebar Workers. International Journal of Environmental Research and Public Health. 2017;14(9):1055. doi:10.3390/ijerph14091055.
    CrossRef
42. Wong DP, Chung JW, Chan APC, Wong FK, Yi W. Comparing the Physiological and Perceptual Responses of Construction Workers (Bar Benders and Bar Fixers) In a Hot Environment.Applied Ergonomics. 2014;45:1705–1711.
    CrossRef
43. Kjellstrom T, Holmer I, Lemke B. Workplace heat stress, health and productivity – an increasing challenge for low and middle-income countries during climate change. Global Health Action. 2009;2:1. DOI: 10.3402/gha.v2i0.2047.
    CrossRef
44. Parsons K. Human thermal physiology and thermoregulation. In Human Thermal Environments. 2014; pp. 98-117. CRC Press.
    CrossRef
45. National Institute for Occupational Safety and Health (NIOSH). Emergency responder health monitoring and surveillance (ERHMS). Atlanta, GA: Centers for Disease Control and Prevention. 2018.
46. Luo EK.Hot and cold: Extreme temperature safety. 2018; https://www.healthline.com/health/extreme-temperature-safety retried on 1^st December 2021.
47. Pogacar T, Casanueva A, Kozjek K, Ciuha U, Mekjavic IB, BogatajKL, Crepinšek Z. The effect of hot days on occupational heat stress in the manufacturing industry: Implications for workers’ well-being and productivity. International Journal of Biometeorology. 2018;62(7):1251–1264.
    CrossRef
48. ILO. Working on a Warmer Planet: The Impact of Heat Stress on Labour Productivity and Decent Work. International Labour Office: Geneva, Switzerland.2019.
49. Steenland K, Zhao L, Winquist A. A cohort incidence study of workers exposed to perfluorooctanoic acid (PFOA). Occup Environ Med.2015;72(5):373-80. PMID: 25601914. doi:10.1136/oemed-2014-102364.
    CrossRef
50. Levy BS, Roelofs C. Impacts of climate change on workers’ health and safety. In Oxford Research Encyclopedia of Global Public Health.2019.
    CrossRef
51. Roelofs C. Without warning: Worker deaths from heat 2014–2016. New Solutions.2018;28(2):344–357.
    CrossRef
52. Marinucci GD, Luber G, Uejio CK, Saha S, Hess JJ. Building resilience against climate effects: A novel framework to facilitate climate readiness in public health agencies. International Journal of Environmental Research and Public Health. 2014;11:6433–6458.
    CrossRef
53. Occupational Safety and Health Administration (OSHA). Emergency preparedness and response. Washington, DC. 2018.
54. Roghanchi P, Kocsis KC. Challenges in Selecting an Appropriate Heat Stress Index to Protect Workers in Hot and Humid Underground Mines.Safety and Health at Work. 2018;9(1):10-16. ISSN 2093-7911,doi: 10.1016/j.shaw.2017.04.002.
    CrossRef