A critical review of the scientific and empirical literature on indoor heat illness prevention standards

Heat stress has been a longstanding hazard for workers across many industries. Climate change creates new environmental issues for the workplace. Cal/OSHA is preparing a draft standard to minimize heat-related illness and injury among indoor workers. Indoor heat stress could lead to morbidity and mortality of workers as well as economic burdens and impacted productivity to industries. The goal of this research was to identify the existing literature (standards/guidelines and research articles) and discuss if there were sufficient research data available to implement an indoor workplace heat stress prevention standard in California. Existing national and local enforceable standards and recommended guidelines have been collected. Each standard/guideline was evaluated with the metrics of the originating agency, workplace coverage (indoor/outdoor), year established, measurements, and control methods. A comprehensive search of Pubmed and SciFinder databases was conducted for evidence of measurements and control methods to identify, classify, and evaluate them. In conclusion , a Cal/OSHA standard is feasible because the scientific database is adequate. Weather it is practical depends on cost, ease of field management, stake-holder buy-in, and factors outside of the scientific arena. An indoor heat standard should cover all indoor workplaces. American Conference of Governmental Industrial Hygienists (ACGIH) provided the most accurate and precise measurement method, however, required a Wet Bulb Globe Temperature device and several steps to make determination. The control hierarchy with an emphasize on engineering controls should be implemented at all hot workplace. Administrative controls, such as training, work-rest schedule, hydration, and acclimatization, are bottom lines if engineering controls are not feasible. Cooling vest is effective in preventing heat accumulation, however, may not fit other personal protective equipment. Future studies should focus on effectiveness evaluation of existing standards, cost-benefit of measurement and control methods and identification of impacted industries