An Oregon State University study found an association with rising temperatures and increased injury claims that were more pronounced among workers in the agricultural and construction sectors.
The study analyzed about 92,000 accepted claims and found that the claim rate is about 4% higher when the maximum heat index exceeds 75 degrees. The incident rate for agricultural and construction workers is 14% higher.
When the heat index reaches 115 to 119 degrees, the incident rate is 11% higher than the average rate at temperatures of 74 degrees or lower.
“Although it is well understood that the agricultural and construction industries have high rates of traumatic injuries, the results suggest that these industries have progressively higher IRRs as temperature increases,”; the study says. “The question that needs to be investigated is why.”
Researchers said they also found a link between the presence of fire smoke and increased injury claims among all workers. However, when the heat index was included in the same model, the results for fire smoke became “insignificant”.
“This may be due to the high correlation between heat levels and fire smoke or the exposure metrics used for fire smoke,” the study says.
The Biden administration in September 2021 announced that the Department of Labor and the Occupational Safety and Health Administration are implementing a heat-related hazard oversight initiative, launching a rulemaking process to develop a workplace heat standard, and developing a national heat inspection emphasis program.
Earlier in September, California Governor Gavin Newsom signed AB 1643, which creates a study group to analyze the effects of high heat on workers and the state’s economy. The group will be tasked with addressing issues such as the amount of time lost from work due to heat, the frequency of workplace injuries at different temperatures, and potential underreporting of heat-related injuries and illnesses. The final report must be submitted on 1 January 2026.