Developing an Optimal Work–Rest Schedule for Construction Workers in Hot Weather: A Case Study of South China

Working in hot weather exposes construction workers to significant risks of heat-related strain, resulting in decreased labor productivity and increased occupational injuries and illnesses. The establishment of well-designed work–rest cycles serves as an effective strategy for alleviating these risks. This study aims to develop an optimal work–rest schedule for construction workers in hot weather that maximizes labor productivity while safeguarding worker health and well-being. Field studies were conducted at three construction sites in south China during the hot season (May–July 2024). The physiological data of 175 construction workers, along with meteorological data from these construction sites, were synchronously monitored and measured. Machine learning techniques were utilized to accurately estimate two key parameters essential for schedule design, in terms of maximum work duration (MWD) and rate of recovery (ROR). To reflect the variability and uncertainty in real-world construction environments, Monte Carlo simulations were employed to generate a wide range of potential worker environment scenarios. By systematically evaluating different work–rest patterns across these scenarios, the optimal schedule was identified, consisting of a 15-min break after 150 min of continuous work in the morning, and a 20-min break after 140 min of continuous work in the afternoon. This schedule achieves the maximum labor productivity while reducing the occurrence of heat-related incidents. The findings provide a scientific and practical work–rest schedule for the construction industry, offering a viable strategy for heat stress management that enhances both work efficiency and worker protection in heat conditions.