Heat Exposure and Predictors of Heat-Related Illness Symptoms among Outdoor Municipal Workers

Nurul Izzah Abdul Samad (Environmental and Occupational Health Programme, School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia)
Anis Adiba Adnan (Environmental and Occupational Health Programme, School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia)
Nursuhaili Mohd Amin (School of Occupational Safety and Health, Faculty of Allied Health Professions, AIMST University, Bedong 08100, Kedah, Malaysia)
Maisarah Nasution Waras (Department of Toxicology, Pusat Kanser Tun Abdullah Ahmad Badawi, Universiti Sains Malaysia, Kepala Batas 13200, Penang, Malaysia)
Nurul Atikah Che Hasan (Faculty of Ocean Engineering and Technology, Universiti Malaysia Terengganu, Kuala Terengganu 21300, Terengganu, Malaysia)
Nurhidayah Sabri (Faculty of Health Sciences, Universiti Teknologi MARA, Cawangan Pulau Pinang, Kampus Bertam, Kepala Batas 13200, Penang, Malaysia)
Herdianti Hatta (Master in Public Health Study Programme, Faculty of Health Sciences, Universitas Ibnu Sina, Batam 29444, Riau Islands, Indonesia)
Nurul Ainun Hamzah (Environmental and Occupational Health Programme, School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia)

JURNAL KESEHATAN LINGKUNGAN (Journal of Environmental Health)
Vol. 18 No. 1si (2026): JURNAL KESEHATAN LINGKUNGAN

Introduction: Municipal workers who perform outdoor tasks daily are often exposed to hot weather conditions, which may contribute to various heat-related illnesses (HRI). Long working hours in hot and humid environments may affect workers physically through dehydration, fatigue, heat exhaustion, and other symptoms related to heat strain. This study was conducted to assess environmental heat exposure and factors associated with HRI symptoms among outdoor sanitation and maintenance workers. Methods: A cross-sectional study was carried out among 88 outdoor municipal workers in Kota Bharu, Kelantan. Environmental heat exposure was measured using the Wet Bulb Globe Temperature (WBGT) index. Data was collected using a self-administered questionnaire covering sociodemographic characteristics, work-related profiles, and heat-related illness (HRI) symptoms experienced after the work shift. Multiple logistic regression analysis was applied to identify factors associated with HRI symptoms. Results and Discussion: WBGT values recorded during both work sessions ranged from 29.99°C to 30.54°C, were close to or exceeding the recommended occupational exposure limits. Most workers reported at least one mild HRI symptom (96.6%), with fatigue, dizziness, and muscle cramps being the most reported complaints. The analysis showed that effective WBGT (WBGTeff) was significantly associated with HRI symptoms (p = 0.043). Conclusion: Outdoor municipal workers were exposed to considerable environmental heat, which may contribute to heat-related symptoms. Preventive strategies such as adequate hydration and appropriate work-rest arrangements, and heat awareness programs should be strengthened to reduce the risk of heat-related illness among workers.