When It’s Over 90 Degrees, Should Workers Really Be Outside? A California Study Examines the Connection Between Heat and Worker Injury

A recent study by the Institute of Labor Economics highlights the correlation between rising temperatures and worker injuries in California.
By: | August 20, 2021

There’s no denying that temperatures are climbing year after year. Sicily recently saw a day where temperatures reached 120 degrees Fahrenheit temperature — potentially setting the record for Europe’s hottest day.

As this is being written, both the U.S. Pacific Northwest and Eastern Coast are experiencing grueling temperatures and California continues to battle a weeks-long heat wave.

The Institute of Labor Economics, in collaboration with researchers from UCLA and the University of Stanford, dove into the correlation between workplace injuries and temperatures in order to see just how dangerous rising temperatures can be for the workforce.

The researchers gathered 18 years’ worth of claims data from California’s workers’ compensation system along with daily temperatures to compare the results. Here’s what they found.

The Study’s Findings

Heat has a significant impact on worker performance, the study concluded, though this was not a concept that was always understood by employers and employees alike.

The research found that on days when temperatures in California were in the 90-degrees Fahrenheit, workplace injuries and accidents increased by 9%. Similarly, on days when California temperatures were around or exceeded 100 degrees Fahrenheit, workplace injuries increased by 15%.

An imperative finding from the study shows that while workers who work in outdoor settings, like agriculture and construction, are severely impacted by high temperatures, they are not alone. Workers who work indoors, such as those in the manufacturing, warehousing and wholesale are also affected.

Related: Opinion | With Temperatures Reaching Record Highs, We’ve Got to Do More for Our Outdoor Workers

While all workers can face negative impact from high temperatures, the study found that both men and younger workers are at a greater risk of either having an accident or becoming injured on extremely hot days. This finding also applies to those workers who are in indoor settings.

Additionally, low wage workers are also susceptible to these types of workplace injuries due to the nature of their jobs. The study found that the average worker in the bottom 20% of earners was five times more likely to be injured on a day with high temperatures than a worker in the top 20% of earners.

When a worker becomes injured on the job, workers’ compensation and health insurance are only covering a small component of both their lost income and medical bills.

Because of this, the impact of rising temperatures could also be a surging catalyst for income inequality.

California’s Response and Moving Forward

The data is staggering, yet it is estimated extreme heat injuries are severely underreported in the state of California. The study did review a regulation put in place by the state in 2005 that serves as heat illness prevention.

With this regulation, outdoor workers were required to be given opportunities for shade and time out of the sun, as well as have water and heat exhaustion prevention training. Researchers looked at this data and surveyed that while the connection between worker injury and heat was still present, it was not as strong of a correlation as it was before the regulation was put in place.

Moving forward, California and OSHA are currently working on a similar regulation for those workers who primarily work indoors. &

Emma Brenner is a staff writer with Risk & Insurance. She can be reached at [email protected].

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