Climatic heat risk management in construction: A socio-ergonomic theory

Abstract

Theoretical models have been developed for decades in the ergonomics field for understanding the mechanism of heat stress in working environment and development of heat strain in human body. They are however disconnected with management practice where large working population is exposed to climatic heat stress in summer, such as in the context of construction industry. Existing heat stress management in construction sites is being practised in an incremental way, which results in conflicting effects in safety measures. For example, the safety helmet, intended to protect workers from falling objects, often acts as a head heater during hot summer, which puts workers in a dilemma of risking one hazard or another. There is a lack of understanding on which systematic planning could be developed for heat stress management in construction sites. Noting this gap, this paper presents an initial theory that grounded the ergonomic heat stress model into its managerial, social and institutional context of the construction industry. The socioergonomic theory is generated from physiological, environmental and interview data from34 heat illness cases out of a sample of 216 workers of 26 construction sites in Hong Kong over 69 summer days. Using the existing rational ergonomics model of heat stress mechanism as a core, primary causes of heat illness in construction sites are identified, based on which effective interventions and their enablers at management and industrial levels are sorted. The theory serves to explain and predict climatic heat risks and its mitigation measures. Practically it serves to guide systematic assessment, monitoring and mitigation of heat stress risks in construction sites. The theory is open for modification and further development through cross-regional comparative studies.