Heat Stress Risk of Construction Workers in Semi-Arid Coastal Areas: Evidence from East Sumba, Indonesia

Abstract

Extreme heat poses a serious hazard for construction workers in tropical semi-arid regions, affecting safety, productivity, and health. This study investigated heat stress risk perception and contributing factors among 78 construction workers in East Sumba, Indonesia, comprising 40 non-local workers (51.3%) and 38 local workers (48.7%). Data were collected during 2023–2024 through on-site environmental measurements and structured interviews at eight active construction sites. Wet Bulb Globe Temperature (WBGT) measurements indicated consistently high-risk heat exposure conditions, particularly between 11:00 a.m. and 3:00 p.m. Independent-samples t-tests showed no significant differences between local and non-local workers in heat risk perception and preventive awareness (p-values > 0.05). However, local workers demonstrated higher acclimatization and thermal tolerance than non-local workers. Heat-related symptoms were reported by 15 workers (19.2%), including fever, dizziness, excessive thirst, and fainting. Smoking, insufficient sleep, and low body mass index were associated with increased vulnerability. These findings highlight the need for WBGT-based work–rest schedules, shaded rest areas, the provision of drinking water, and targeted heat-stress training, particularly for non-local workers.

Keywords: Heat Stress; Construction Workers; Tropical semi-arid regions; Wet Bulb Globe Temperature (WBGT).