The unstructured nature of the labor-intensive construction industry negatively affects the health of workers. These challenges require a robust health monitoring approach to accurately monitor workers’ overall health status. Recent advancements in wearable technologies and physiological sensing have provided ample opportunities towards an objective and continuous in-field measurement of workers’ physical and mental status. However, these solutions have mostly focused on a particular health condition. There is a lack of holistic health monitoring to understand the impacts of the construction environment on workers’ health conditions (i.e., physical fatigue, mental stress, and exposure to heat stress). In this regard, the present study investigates the feasibility of a multimodal wearable sensing system to comprehensively monitor construction workers’ overall health status during their ongoing work. To this end, five able-bodied workers were prompted to perform specific construction activities (e.g., roofing, loading/unloading) with light and medium physical intensity while exposed to varying levels of heat stress (i.e., caution level, and danger level). During each task, three biosignals, namely photoplethysmography (PPG), electrodermal activity (EDA), and skin temperature (ST), and were collected from the workers through wearable biosensors. To assess their overall health status, various metrics were extracted from PPG (heart rate, heart rate variability), EDA (electrodermal level), and ST (mean skin temperature). Results of correlation analysis elucidated strong correlation between the extracted physiological metrics with respect to workers’ physical fatigue, mental stress, and heat stress exposure. The findings demonstrated the feasibility of a multimodal sensing system for the holistic health monitoring of construction workers.