In the 30 years since the National Institute for Occupational Safety and Health (NIOSH) made major recommendations to prevent work-related heat stress, recent events have raised questions about working safely in hot environments. For example, during the Deepwater Horizon response and cleanup of 2010, crews worked through the hot Gulf of Mexico summer. That event, and the evaluation of accumulated research and literature characterizing effects of working with heat stress, prompted NIOSH to revise its guidance document Criteria for a Recommended Standard:Occupational Exposure to Heat and Hot Environments after an extensive scientific review. Although the recommended alert and exposure limits still protect workers in hot environments and remain unchanged, the revised document includes updated research findings, training, and intervention tools.
Working in hot environments—both outdoors and indoors—increases the risk of heat stress, which can cause injuries, disease, reduced productivity, and even death. To continue to protect workers from this serious work-related hazard, NIOSH investigators collaborated with other scientific experts, partners, and the public, through a request for comments and peer review, to revise the criteria document.