As global temperatures climb, so do heat-related workplace injuries — now estimated at around 28,000 annually, according to a new study published in Environmental Health. Researchers from Harvard and George Washington University examined hundreds of thousands of federal workplace injury reports, uncovering a clear link between higher temperatures and increased risk of on-the-job accidents.
Injury rates begin to rise at temperatures around 85°F and surge significantly once they pass 90°F. The risks are even more pronounced in states lacking workplace heat safety regulations, according to Stateline.
For example, in states without occupational heat rules, injury risk jumped by 22% when the heat index reached 110°F or more. In contrast, the increase was just 9% in states with heat protections in place — namely California, Colorado, Minnesota, Oregon, and Washington.
The study also compared states in the Western U.S., revealing similar gaps in injury rates between those with and without heat rules, even when accounting for regional climate differences.
Both outdoor jobs like construction and agriculture, and indoor roles in sectors like manufacturing and warehousing, showed heightened injury risks. This suggests that extreme heat doesn’t just affect outdoor labor; it impacts a wide range of industries.
OSHA has taken steps toward addressing this growing threat. In 2023, the agency proposed new heat safety standards under the Biden administration, aiming to mandate employer monitoring of heat hazards and implement clearer protective measures. A public comment period on the proposed rules is ongoing through the end of October.
As climate change drives more frequent and intense heat waves, researchers caution that injury risks are likely to keep rising unless stronger workplace protections are implemented.
