The average U.S. warehouse measures about 36,300 square feet, up nearly 15% from a decade ago, according to CoStar. Newer ones are far bigger, with 30-to-40-foot ceilings and footprints of “10 to 20 football fields,” Ponsen said. “It’s almost like air conditioning an entire farm.”
Doing so is often reserved for perishables.
“When the space is for food, they maintain warehouses at a certain temperature because the government checks to make sure the food doesn’t spoil,” veteran warehouse worker Victor Ramirez said in Spanish.
When the space is for food, they maintain warehouses at a certain temperature.
Victor Ramirez, longtime california warehouse worker
Of the 10 warehouses across California’s Inland Empire where he has worked since 2004, Ramirez recalled one with air conditioning in the work area: a major retailer facility that handled frozen and refrigerated products, where even delivery containers were kept out of the sun. His current workplace is a packaging company facility that feels cool only in the break area.
Many facilities are prone to hot spots, particularly on upper levels and by loading dock doors, according to workers, regulators and industry experts. Common climate-control measures like fans can improve air flow but usually don’t reduce internal temperatures much. Even in warehouses with cooling systems, some indoor areas can exceed 80 degrees on hot days.
One week last summer when outdoor highs ranged from 106 to 112 degrees in San Bernardino, workers at the Amazon air hub measured indoor temperatures as high as 89, according to a report by the Warehouse Worker Resource Center, a nonprofit advocacy group in the Inland Empire.
Amazon disputed the readings, saying indoor temperatures didn’t surpass 78 degrees that week or 77 degrees in Rivera’s work area the day he spoke with NBC News. The company said the site is “temperature controlled with full air conditioning” and hasn’t had a work-related heat illness this year.
“Our heat-related safety protocols are robust and often exceed industry standards and federal OSHA guidance,” said Amazon spokesperson Maureen Lynch Vogel. “Amazon is one of only a few companies in the industry to have installed climate control systems in our fulfillment centers and at every air hub,” including the San Bernardino one, she said.
Nonbinding federal guidelines warn that heat-related illnesses become risky for those doing “strenuous work” when the “wet bulb globe temperature” — a metric that factors in humidity, wind speed and radiant heat from sunlight and machinery — passes 77 degrees. California’s proposed indoor heat rule would kick in at 82 degrees.
Of the five fastest-growing warehouse construction markets — Dallas, the Inland Empire, Houston, Chicago and Atlanta, respectively, according to CoStar — four are in the Sun Belt, which has seen both rapid population growth and scorching heat in recent years. The demographic influx has required more inventory space to serve retail customers, often in spread-out areas with large parcels of undeveloped land, CoStar’s Ponsen said.
Albertsons, Amazon, Lowes, Marshalls, Target, Walmart and other major brands all operate out of massive warehouses exceeding 1 million square feet in the Atlanta, Dallas, Houston or Phoenix areas — some in more than one of those markets — according to the research firm Predik.
While Amazon built the San Bernardino facility where Rivera works, many companies that use warehouse space frequently rent it from others, and CoStar data shows tenants pay for electricity in more than 95% of industrial leases signed this year.
Additionally, many warehouse HVACs are retrofits that require navigating workplace safety regulations, and some climate-control systems produce moisture that can damage or rust equipment if not installed properly, said Barton James, CEO of Air Conditioning Contractors of America, an HVAC-focused trade group.
“Someone’s looking for: What’s the least costly way to create a space to store my goods?” said James, adding that cooling investments often “take a long time to pencil out.”
Low-cost, well-established measures — like access to water, rest periods and cool zones — can make a difference, said Thomas Bernard, a public health professor at the University of South Florida who has helped employers develop heat-stress management programs. Asked during a 2019 congressional hearing about the costs of doing so, he estimated it “on the order of implementing any other health and safety program.”
A long, hot wait
Back in 2012, Ramirez was working at a Walmart warehouse when he joined colleagues from a Walmart supplier’s distribution center nearby for part of a six-day march from Ontario, California, to Los Angeles to protest heat-related working conditions at the latter facility.
A decade later, he rallied with Inland Empire Amazon Workers United, a group that includes Rivera and many of his co-workers, when they walked out of the San Bernardino hub last summer, demanding higher pay and better relief from the heat.
“Taking care of associates is always a top priority,” said a Walmart spokesperson, noting that the workers who marched 11 years ago didn’t work directly for the company and that Walmart has long offered heat illness prevention training that remains “an ongoing focus.”
It’s not just temperature that you have to be concerned about, it’s also the nature of the work.
Debbie Berkowitz, former senior OSHA official
Getting employers to institute more rest time on hot days has always been the biggest challenge, Ramirez said: “Stopping for five minutes every hour so that people can relax and go in the cool air, then go back to work — that’s what we’re fighting for.”
The warehousing sector’s injury rate has grown in the past decade, in some areas hitting levels more than twice that of private industry overall. Regulators, labor advocates and investigators have faulted the pace and production quotas many warehouse workers face, among other factors. A California law limiting such quotas took effect last year, and Minnesota passed a similar bill this year. Last month OSHA announced a national warehouse “emphasis program” over injury rates that will increase inspections, including examining heat exposure.
“Indoor workplaces that are the most dangerous for heat are those where it’s not just temperature that you have to be concerned about, it’s also the nature of the work,” said Berkowitz, the former OSHA official.
Few warehouse operators have faced as much scrutiny over injury concerns, heat-related or otherwise, as Amazon. State and federal regulators have fined the company for warehouse safety violations in recent years. Federal prosecutors are examining “possible fraudulent conduct designed to hide injuries from OSHA and others.” Sen. Bernie Sanders (I-Vt.) began investigating Amazon’s warehouse practices in June, citing productivity rates and employee tracking as alleged contributors to “dangerous and illegal conditions.”
