Heat Stroke Fatalities: Lessons for Prevention

The Bureau of Labor Statistics recorded an average of 33 heat-related fatalities in the U.S. annually between 2003 and 2009, with a range of 18 - 47. Construction, agriculture, and natural resources extraction accounted for the majority of fatalities, who were overwhelmingly male and disproportionately Latino. OSHA's enforcement of heat stress is conducted under general duty clause provisions, and the Office of Occupational Medicine provides expert consultation to compliance officers on request to determine the cause of workplace fatalities.

Five heat stroke fatalities were evaluated by the occupational physicians within a 12 month period to identify common themes and opportunities for prevention.

Heat stroke fatalities occurred early in job tenure, involving workers who had not been appropriately acclimatized. Heat prevention programs, including recommendations for rest breaks and provision of water, acclimatization, and were deficient. Pre-existing medical conditions were not recognized or taken into account for purposes of acclimatization, and virtually no medical evaluations had been conducted.

Broad outreach to initiate preventive measures remains an important need. In addition, primary care evaluation and worker education that identifies important risk factors and allows workers to more gradually work into a job are needed. Two challenging messages are: 1) how to integrate widely available measures of temperature and humidity with additional information about radiant heat sources and heat generated by physical exertion and 2) how to clarify that, while hot and dry is ALWAYS an emergency, heat stroke can occur in persons who are still sweating but who will have altered mental status.