Workers in tropical and subtropical regions are exposed not only to hot and humid weather but also to occupational stressors that can exacerbate heat stress, leading to physiological, cognitive, and psychological consequences.
Objective
This study investigated the relationship between thermal stress, mental workload, and occupational burnout among oil industry employees during summer work shifts.
Methods
A total of 234 male employees were selected through convenience sampling. Participants completed demographic questionnaires, the Maslach Burnout Inventory, and the NASA-TLX mental workload questionnaire. Heat stress and environmental variables were measured with a WBGT device in accordance with the ISO 7243:2017 standard for assessing occupational heat stress. Measurements were conducted under indoor and outdoor conditions. Data analysis included Spearman correlation, independent t-tests, ANOVA, and confirmatory factor analysis to explore direct and indirect relationships between workload, burnout, and their dimensions.
Results
The average WBGT index exceeded ISO occupational exposure limits in 80.77% of cases. Machine operators, control room engineers, firefighters, and maintenance personnel were most frequently exposed to excessive heat. A significant negative relationship was found between work experience and emotional exhaustion among employees within the ISO-recommended exposure range. Cognitive workload, particularly time pressure and mental demand, was strongly associated with occupational burnout.
Conclusion
Heat stress indirectly influenced occupational burnout through increased cognitive workload. Greater mental pressure corresponded with higher scores across other workload subscales and burnout dimensions. These findings underscore the need for preventive strategies and improved work–rest schedules in hot industrial environments.
Intergovernmental Panel on Climate Change (IPCC). Climate Change 2021 – The Physical Science Basis [Internet]. Vol. 2, Contribution of working group I to the sixth assessment report of the intergovernmental panel on climate change. Cambridge: Cambridge University Press, 2023, 2391 p. Available from: https://www.cambridge.org/core/product/identifier/9781009157896/type/book. https://doi.org/10.1017/9781009157896
2.
PogačarTCasanuevaAKozjekK, et al.The effect of hot days on occupational heat stress in the manufacturing industry: implications for workers’ well-being and productivity. Int J Biometeorol2018 Jul 1; 62: 1251–1264.
3.
MoriKNaganoCFukuzawaK, et al.Mitigation of heat strain by wearing a long-sleeve fan-attached jacket in a hot or humid environment. J Occup Health2022; 64: e12323.
4.
El KhayatMHalwaniDAHneinyL, et al.Impacts of climate change and heat stress on farmworkers’ health: a scoping review. Front Public Heal2022; 10: 782811.
5.
ParsonsK. Human thermal environments: the effects of hot, moderate, and cold environments on human health, comfort and performance. Boca Raton: CRC press, 2007.
6.
CheungSSMcLellanTMTenagliaS. The thermophysiology of uncompensable heat stress: physiological manipulations and individual characteristics. Sport Med2000; 29: 329–359.
7.
KaramiMMehrparvarAHDehghani TafatiA, et al.The relationship between heat stress on the vital factors and cognitive function Sarcheshmeh copper smelter workers in 2018. Occup Med Q J2018; 10: 10–21.
8.
AbbasiAMMotamedzadeMAliabadiM, et al.The impact of indoor air temperature on the executive functions of human brain and the physiological responses of body. Heal Promot Perspect2019; 9: 55–64.
9.
AnsariMMazloumiAAbbassiniaM, et al.Heat stress and its impact on the workers’ cortisol concentration: a case study in a metal melding industry. J Heal Saf Work2014; 4: 59–68.
10.
khanijazaniRTabatabaeiiSSeyed MehdiSK. Ergonomic study of the relationship between job stress and harmful factors in the cement industry. Occupational Health Journal2016; 13: 58–67.. Available from: http://ioh.iums.ac.ir/article-1-1495-fa.html.
11.
LanLLianZPanL, et al.Neurobehavioral approach for evaluation of office workers’ productivity: the effects of room temperature. Build Environ2009; 44: 1578–1588.
12.
ChiddaychaMWainipitapongS. Mental health among Thai medical students: preadmission evaluation and service utilization. Heal Sci Reports2021; 4: e416.
13.
Hoveizi1MGF. Determination and comparison of TWL and WBGT thermal stress indices of an onshore drilling rig workers in ahvaz [internet]. Journal of Agrometeorology2018; 20: 1–10.. Available from: http://ioh.iums.ac.ir/article-1-1425-en.html.
14.
ZhangXWeiNLiM, et al.Sickness presenteeism, job burnout, social support and health-related productivity loss among nurses in the Chinese nurses’ health cohort study (TARGET): a cross-sectional survey. Int J Nurs Stud2025; 162: 104962.
15.
GravanteFPucciarelliGSperatiF, et al.Risk factors of anxiety, depression, stress, job burnout, and characteristics of sleep disorders in critical care nurses: an observational study. Aust Crit Care2025; 38: 101165.
16.
MehdiSAbbasDAliAA. A study on the extent and causes of employee burnout in satellite jobs (study case: Iranian continental shelf oil company-siri region). Industrial Law Journal1978; 7: 239–263.
17.
RonyMKKAlamgirHM. High temperatures on mental health: recognizing the association and the need for proactive strategies—A perspective. Heal Sci Reports2023; 6: e1729.
18.
YeomanKWeakleyADuBoseW, et al.Effects of heat strain on cognitive function among a sample of miners. Appl Ergon2022; 102: 1–23.
19.
WangXLiDMenassaCC, et al.Investigating the effect of indoor thermal environment on occupants’ mental workload and task performance using electroencephalogram. Build Environ2019; 158: 120–132.
20.
LinNWRamirez-CardenasAWingateKC, et al.Risk factors for heat-related illness resulting in death or hospitalization in the oil and gas extraction industry. J Occup Environ Hyg2024; 21: 58–67.
21.
SpectorJTMasudaYJWolffNH, et al.Heat exposure and occupational injuries: review of the literature and implications. Curr Environ Heal Reports2019; 6: 286–296.
22.
MorrisseyMCBrewerGJWilliamsWJ, et al.Impact of occupational heat stress on worker productivity and economic cost. Am J Ind Med2021; 64: 981–988.
GolbabaieFMonazam EsmaieliMRHemmatjouR, et al.Comparing the heat stress (DI, WBGT, SW) indices and the men physiological parameters in hot and humid environment [internet]. IJHE2012; 5: 245–252.. Available from: http://ijhe.tums.ac.ir/article-1-31-en.html.
AfshariDNourollahi-DarabadMShiraliGA. Applicability of WBGT index in determining the allowable working time in hot climate conditions. J Heal Saf Work2021; 11: 1233–1238.
28.
American Conference of Governmental Industrial Hygienists (ACGIH). Heat Stress and Strain: TLV® Physical Agents. Cincinnati, OH: ACGIH, 2009.
29.
WinslowCE. The kata thermometer as a measure of the effect of atmospheric conditions upon bodily comfort. Science1916; 43: 716–719.
30.
EmiliaIExtremeraRAPecinoCV, et al.Prevalence and risk factors of burnout syndrome among Spanish police officers. Psicothema2013; 25: 488–493.
31.
VojvodicARDedicG. Correlation between burnout syndrome and anxiety in military personnel. Exp Appl Biomed Res2020; 21: 59–65.
32.
HernandezBStanleyBMillerL. Job embeddedness and job engagement: recommendations for a supportive social work environment. Hum Serv Organ Manag Leadersh Gov2014; 38: 336–347.
33.
Maertz JrCPGriffethRW. Eight motivational forces and voluntary turnover: a theoretical synthesis with implications for research. J Manage2004; 30: 667–683.
34.
Leana IIICRVan BurenHJ. Organizational social capital and employment practices. Acad Manag Rev1999; 24: 538–555.
35.
MoynihanDPPandeySK. The ties that bind: social networks, person-organization value fit, and turnover intention. J Public Adm Res Theory2008; 18: 205–227.
36.
TsaiWGhoshalS. Social capital and value creation: the role of intrafirm networks. Acad Manag J1998; 41: 464–476.
37.
BoyasJWindLHKangSY. Exploring the relationship between employment-based social capital, job stress, burnout, and intent to leave among child protection workers: an age-based path analysis model. Child Youth Serv Rev2012; 34: 50–62.
38.
BoyasJFWindLHRuizE. Organizational tenure among child welfare workers, burnout, stress, and intent to leave: does employment-based social capital make a difference?Child Youth Serv Rev2013; 35: 1657–1669.
39.
AnastasiouSBeliosE. Effect of age on job satisfaction and emotional exhaustion of primary school teachers in Greece. Eur J Investig Heal Psychol Educ2020; 10: 644–655.
40.
SchroederSKellyDLeightonK. Influence of years of experience and age on hospital workforce compassion satisfaction, anxiety, depression, stress, and burnout during pandemic: implications for retention. Psychol Health Med2023; 28: 1741–1754.
41.
YangBYaoHYangP, et al.Effects of thermal and acoustic environments on workers’ psychological and physiological stress in deep underground spaces. Build Environ2022; 212: 108830.
42.
KovatsRSHajatS. Heat stress and public health: a critical review. Annu Rev Public Heal2008; 29: 41–55.
43.
KellerMCFredricksonBLYbarraO, et al.A warm heart and a clear head: the contingent effects of weather on mood and cognition. Psychol Sci2005; 16: 724–731.
44.
YousefiFAzamKZakerianSA. Mental workload and determination of its relationship with situation awareness and work experience among taxi drivers. J Occup Hyg Eng2019; 6: 44–53.
45.
LeeHIParkSLimJ, et al.Influence of driver’s career and secondary cognitive task on visual search behavior in driving: a dual-task paradigm. Adv Phys Educ2015; 5: 245–254.
46.
ListopadIWMichaelsenMMWerdeckerL, et al.Bio-psycho-socio-Spirito-cultural factors of burnout: a systematic narrative review of the literature. Front Psychol2021; 12: 722862.
47.
YouXHuangJWangY, et al.Relationships between individual-level factors and burnout: a meta-analysis of Chinese participants. Pers Individ Dif2015; 74: 139–145.
48.
MoustafaMAElrayahMAljoghaimanA, et al.How does sustainable organizational support affect job burnout in the hospitality sector? The mediating role of psychological capital. Sustainability2024; 16: 40.
49.
KlineCE. The bidirectional relationship between exercise and sleep: implications for exercise adherence and sleep improvement. Am J Lifestyle Med2014; 8: 375–379.
50.
EkiciÖ. Association of stress, anxiety, and depression levels with sleep quality in patients with temporomandibular disorders. CRANIO®2023; 41: 407–415.
51.
González-AlonsoJTellerCAndersenSL, et al.Influence of body temperature on the development of fatigue during prolonged exercise in the heat. J Appl Physiol1999; 86: 1032–1039.
52.
NyboLNielsenB. Middle cerebral artery blood velocity is reduced with hyperthermia during prolonged exercise in humans. J Physiol2001; 534: 279–286.
53.
NyboL. Hyperthermia and fatigue. J Appl Physiol2008; 104: 871–878.
54.
LõhmusM. Possible biological mechanisms linking mental health and heat—a contemplative review. Int J Environ Res Public Health2018; 15: 1515.
55.
SunGQianSJiangQ, et al.Hyperthermia-induced disruption of functional connectivity in the human brain network. PLoS One2013; 8: e61157.
56.
AbareshiFSalimiFFarniaF, et al.The impact of mental workload, work-related and socio-demographic factors on job burnout among emergency medical staff. Work2022; 72: 1269–1277.
57.
ZanabazarAJigjiddorjS. Relationships between mental workload, job burnout, and organizational commitment. In: SHS Web of conferences. Les Ulis: EDP Sciences, 2022, pp.1003.
Rubio ValdehitaSLópez NúñezMILópez-Higes SánchezR, et al.Development of the CarMen-Q questionnaire for mental workload assessment. Psicothema2017; 4: 570–576.
60.
KeserAYılmazG. Workload, burnout, and job satisfaction among call center employeesJournal of social policy conferences. Istanbul: Istanbul University, 2014, pp.1–13.
61.
LiuHLLoVHWEI. An integrated model of workload, autonomy, burnout, job satisfaction, and turnover intention among Taiwanese reporters. Asian J Commun2018; 28: 153–169.
