High temperatures contribute to thousands of workplace injuries each year, according to a recent study out of Harvard University and George Washington University.

Researchers examined 2023 data from OSHA’s Injury Tracking Application for businesses with 100 or more employees, primarily in high-hazard industries.

Each injury was geo-coded and matched with high-resolution weather data for the specific injury date, the study indicated.

In addition to discovering that around 28,000 injuries were associated with hot weather, the researchers found that the risk of injury increased when the heat index was around 85° F, rising even more when the heat index reached 90° F or higher.

Injuries related to extreme heat exposure were seen across nearly all industry sectors, including jobs performed indoors.

Employees in states with workplace heat exposure regulations appeared to have a lower risk of injury on hot days.

“Most heat-related injuries are not recorded as such, so the 28,000 workplace injuries every year are probably an underestimate,” senior study author David Michaels, an environmental and occupational health professor at GW and former OSHA administrator, said in a press release.

Researchers said the findings underscore the value of protecting workers from extreme heat.

The study was published in the journal Environmental Health.