A new study led by UCLA’s R. Jisung Park, UCLA Luskin School of Public Affairs, shows that hot weather significantly increases the risk of both outdoor and indoor workplace accidents and injuries. It is estimated that high temperatures already cause about 15,000 injuries per year in California, and this number is set to increase as climate change raises average high temperatures.

The new report compares 11 million claims in the California workers’ compensation system to high-frequency local weather data. Results show that on days with a high temperature above 90 degrees Fahrenheit, workers have a 6% to 9% higher risk of injury than days when the high temperature is in the 50s or 60s. When high temperatures surpass 100 degrees Fahrenheit, the risk increases 10% to 15%. These conclusions may seem obvious for people working outdoors, but they also apply to indoor workplaces. High temperatures above 95 degrees Fahrenheit increase indoor injury risk by approximately 7% compared to days with high temperatures in the low 60s.

Researchers also found that heat-related workplace injuries impact young people, men, and lower-income workers the most. This is possibly because they are more likely to hold jobs with more physical risks associated, such as construction or manufacturing. The study presents many other important conclusions, including the financial cost of heat-related injuries; the financial burden could be as much as $1.25 billion per year in California alone.

The report is currently available through the Institute of Labor Economics which shares working versions of potentially influential research prior to its publication in academic journals.

Learn more at UCLA Newsroom.