Extreme heat is transforming work

Why breaks, water, and shade for a sea of US workers could trigger the next big labor battle.

It’s been a summer of record-breaking heat waves. In July, a heat dome smothered much of the South, while Phoenix sweltered under a 31-day streak of temperatures above 110 degrees.

Another wave of searing temperatures is currently sweeping the central US, with the heat index — a metric that combines relative humidity with air temperature to gauge what the temperature actually feels like — creeping above 120 degrees in many cities.

The Midwest may be used to acute winters, but not such searing summers: Some buildings have no air conditioning, and infrastructure such as asphalt roads may not have been built with extreme heat in mind.

As the mercury rises, many US jobs become magnitudes more difficult and dangerous — and not just on construction sites and farm fields, where the majority of heat-related deaths happen. Many workers toiling in places without sufficient cooling or ventilation face high risk, too, including those in factories and warehouses, restaurant employees, and delivery drivers and gig workers exposed to dangerous temperatures as they lug packages out in the sun. Even people who work in indoor environments with cooling mechanisms are at risk, given that faulty or weak HVAC systems are common — as teachers across the country are experiencing. The list of jobs where heat can be a health hazard is endless.

From 2017 to 2022, 121 workers died from heat, according to the federal Occupational Safety and Health Administration (OSHA), though the agency acknowledges that this is likely an undercount. The Bureau of Labor Statistics has recorded another almost 34,000 work-related heat injuries and illnesses that required time away from the job between 2011 and 2020. This summer, Eugene Gates, a 66-year-old letter carrier in Dallas, died on the job on a June day when the temperature reached 97 degrees, and a month later, Dario Mendoza, a 26-year-old farm worker, died after working in the fields amid the Phoenix area’s historic heat wave.

“Many people are saying that this summer feels worse than the summer before,” says Mayra Reiter, project director of occupational safety and health for Farmworker Justice, a worker protection nonprofit. “And it’s making people work in the fields that much harder — people are feeling unsafe.”

The recent spate of heat injuries and deaths among workers is just a preview of what’s to come as climate change continues to send summer temperatures soaring in many US cities. By 2050, some will see their average summer highs rise by as much as 6 degrees. According to a report from the Environmental Protection Agency, wildfire smoke — and even increased risk of diseases from insects such as ticks and mosquitoes, as the warmer weather expands their habitats — will add extra strain to outdoor workers. Indoor workers won’t be exempt from peril either, as buildings with poor insulation and ventilation become ovens during heat waves.

The far-reaching ripple effects of climate change will impact where we can work, when we can work, and how long we can work. Yet there’s no federal regulation setting a threshold for when heat becomes too dangerous for employees to work, or even what employers are required to provide their workers in those conditions — such as water, more frequent breaks, shade, or air conditioning.

For many workers, there’s simply no relief in sight.

How heat harms your health — and how it can make work deadly

There’s no single temperature at which physical exertion becomes risky for everyone. But researchers have found that at a wet bulb globe temperature — a reading that includes humidity, wind speed, whether there’s direct sun exposure, and more — of about 95 degrees Fahrenheit, even the most fit people will overheat. Exposure to that level of heat for as little as six hours could result in death.

Heat begins impacting how efficiently we can work, however, long before the temperature reaches 95 degrees. It varies by region, but in the US the optimal temperature for physical outdoor work is 57.7 degrees. Above that point, productivity starts to decline. It goes to show how quickly heat impacts our bodies.

As a worker overheats, they start feeling weak and dizzy. Their speech may slur. These first signs can lead to heat stroke, as well as rhabdomyolysis — in which muscle tissue breaks down — or even a heart attack. There are more long-term effects, too. A person’s heat tolerance can shrink after they suffer a heat stroke, and scientists are also looking into a possible link between working in heat and kidney disease that’s been observed among agricultural workers.

Temperatures also don’t have to be very high for strenuous work to become deadly. The lack of heat acclimatization all too frequently kills workers; the majority of workers who die from heat do so in the first few days at work. “A lot of workers will actually end up in heatstroke during the first week on the job,” says Brenda Jacklitsch, a health scientist at the National Institute for Occupational Safety and Health (NIOSH).

Extreme heat is also affecting productivity. According to a 2022 study by The Lancet, which is tracking the relationship between climate change and public health, about 470 billion hours of labor were lost in 2021 due to extreme heat. The US alone lost 2.5 billion hours, mostly in the construction, manufacturing, service, and agriculture sectors. “Workers slow down,” says Shouro Dasgupta, an environmental economist and a co-author of The Lancet report. “They either have to work fewer hours or they put less effort during the hours they can work.” Limited work hours will likely ripple down to all parts of the economy; it could affect the pace and availability of consumer goods and services, slow down delivery orders, and delay air travel.

Across the country, airport ground services workers, whether it’s cabin cleaners, baggage handlers, or others who have to be out on the tarmac, have reported facing vicious heat on the job. Rashele Bates, a 26-year-old who cleans plane cabins at the Charlotte, North Carolina airport and who is an active member of the Service Employees International Union (SEIU), told Vox she felt sick and nauseous on the job one day in late July after she and a coworker had been cleaning for about three hours without a proper break. Bates vomited, and her coworker passed out and went to the hospital.

“I’m sitting there drowning in sweat,” Bates recalls. The air conditioning isn’t always turned on in the plane while they work, Bates says, nor is there any air conditioning on the jet bridge connecting the plane to the terminal, where she and her coworker fell ill. Bates and a coalition of other airport workers sent a petition to the airline contractor she works for, Jetstream Ground Services, demanding water bottles and functioning air conditioning in each break room. The SEIU is also supporting legislation to improve labor conditions at airports. Jetstream Ground Services did not respond to a request for comment.

There’s no great mystery on how to address heat illness in the workplace. NIOSH, which operates under the Centers for Disease Control, published its first recommended standards on workplace heat safety back in 1972, and the recommendations haven’t changed much since.

“A lot of the work that’s done is not necessarily rocket science,” said Andrew Levinson, director of standards and guidance at OSHA. “It’s making sure people have water, rest, shade, and that they can ease into work that first week to make sure that they’re adequately acclimatized.”

Why don’t we have workplace heat protection laws?

About half of states could make their own heat standards for the workplace, but only California, Oregon, Washington, Colorado, and Minnesota have done so. In California, an 80-degree heat index triggers employer requirements for regular rest, shade, and water for outdoor workers. Oregon’s heat safety rules, which Reiter of Farmworker Justice said are the country’s strongest, also kick in at 80 degrees, and apply to indoor workers, too.

Texas, meanwhile, is going in the other direction. Governor Greg Abbott signed a bill in June that bans local ordinances going beyond state-level workplace safety rules, after Austin and Dallas had passed ordinances in 2010 and 2015, respectively, mandating more frequent water breaks for construction workers. On a state level, employers are not required to give any breaks to employees. Texas is the most lethal state for heat-related deaths at work — according to the Bureau of Labor Statistics, which also keeps track of heat deaths on the job, 42 people have died there since 2011.

A federal OSHA heat standard is still years away, and not because the agency isn’t aware of the problem. It began working on a proposed rule in 2021, but creating a new standard is notoriously hard because Congress requires the agency to follow a long, labyrinthine process. For example, it must do a cost-benefit analysis, calculating the cost not just to the agency but for all affected industries as well, and go through multiple rounds of public comment.

“That doesn’t mean that the agency is not out there, shouting from the rooftops on the importance of this,” says Levinson, who added that a lot of workers are calling on OSHA to develop heat standards quickly.

The agency also has to contend with political headwinds. The conservative stance on workplace safety rules is broadly that they shouldn’t exist. “Republican administrations don’t do OSHA rules,” says Jordan Barab, a former deputy assistant secretary of labor at the agency under the Obama administration who now publishes a workplace safety newsletter.

In the absence of a heat standard, OSHA has been deploying the “General Duty” clause — an all-purpose rule that employers must provide a workplace free from “recognized hazards.” There are four steps to the clause, though, and OSHA has to build its case for proving each one. “These cases are very legally vulnerable,” says Barab.

Reiter of Farmworker Justice says that OSHA could issue an emergency heat standard while it works on issuing a more permanent standard, but rules like these have been successfully challenged in court. Instead, Reiter’s group, along with a number of unions, are backing a federal bill, recently introduced in the Senate, that would give OSHA a year to issue an interim standard and make it harder to challenge. The bill has won support from a number of Democratic lawmakers.

The Coalition of Immokalee Workers (CIW), which advocates for farm workers in Florida and beyond, isn’t waiting on the federal government. In 2011, the group launched the Fair Food Program, which sets stronger labor standards, including heat standards, on farms. So far more than 20 crop growers, along with Burger King, McDonald’s, Whole Foods, Trader Joe’s, and other large food companies, have signed on.

Gerardo Reyes Chavez, an organizer with CIW and a former farmworker himself, says the difference between conditions on farms signed up with the program and those that aren’t are like night and day. “Before, you didn’t have any way to protect yourself, you were basically down to your luck. But the way I see it, human rights shouldn’t depend on luck.”

Giorgio Viera/AFP via Getty Images

Other unions — including the United Steelworkers, the Teamsters, the SEIU, the ROC United (which advocates for restaurant workers), National Nurses United, and more — are taking up regulations directly with major employers: Recently, UPS drivers unionized with the Teamsters won a contract that, among other changes, requires new company vehicles to have air conditioning. Many existing delivery cars will also be retrofitted with AC, fans, and vents.

Some employers and industry representatives are less than thrilled about a looming OSHA heat standard. The American Farm Bureau Federation, a trade association representing farm producers — an industry with some of the highest numbers of heat-related worker injuries and deaths — has argued that the General Duty clause already protected workers and questioned whether new regulations could be implemented “without imposing new, onerous burdens on farmers and ranchers that will lead to economic losses.” It then implored the agency to focus on “the responsibility on the individual employee and the personal health choices that are made outside of the workplace,” a sentiment that has been echoed by other pro-business groups. The organization declined an interview request for this story.

It goes to show how heat isn’t necessarily what’s making workers sick, Barab says. “It’s really more employers’ refusal to implement measures to protect workers. That’s killing workers.”