For farmworkers, delivery personnel, and construction crews, high temperatures can also mean heat exhaustion and related maladies. Between 1992 and 2016, excessive heat killed 783 US workers and seriously injured 69,374, according to the BLS.

As the climate changes, heat waves are poised to get longer and more intense. That means more workers will face triple-digit temperatures, often for single-digit wages, threatening lives and livelihoods.

While much of the rest of the workforce is in air-conditioned offices and stores, they’re not immune to the economic blows from climate change. By 2028, climate change will cost the US $360 billion per year, about half the expected growth of the economy, according to the Universal Ecological Fund. Much of this is due to health costs.

Researchers are starting to realize just how costly high temperatures are, and workers are now fighting back for cooler conditions.

Extreme heat is costly for workers and the economy as a whole

A huge slice of the US economy requires workers being outdoors and vulnerable to extreme temperatures. There are almost 5 million employed in transportation and logistics, more than 1.3 million farmworkers, more than 7 million working in construction, and more than 600,000 in mining. (Both open pit mines and shaft mines can get extremely hot.)

Rising temperatures have an impact on productivity well before they become dangerous. Economist R. Jisung Park reported that worker productivity declines by 2 percent for every degree Celsius above room temperature. It’s a worldwide phenomenon, with the hottest regions getting hit the hardest. The heat can dehydrate laborers, and higher temperatures demand more frequent breaks.

A 2014 study from the Rhodium Group found that the largest economic losses from climate change in the United States will come in the form of lost labor productivity.

According to the Environmental Protection Agency, the United States will lose 1.8 billion labor hours across the workforce in the year 2100 due to extreme temperatures under a business-as-usual climate change scenario. That adds up to $170 billion in lost wages.

But laborers aren’t the only ones vulnerable to heat. Researchers at the London School of Economics found that urban areas also pay a price for high temperatures, even among indoor office workers. They found that in London, a warm year could cost the city’s economy upward of 2.3 billion euros in productivity. Workers make more mistakes and act more slowly as temperatures rise above their optimal range. You can also see this effect in factories.

Worker protections from high temperatures are sorely lacking