The lunch break had just begun Thursday at the NovelAire Technologies manufacturing plant off South Choctaw Drive in Baton Rouge, but some of the guys heading off the factory floor had an extra task to finish before they ate and took a bathroom break.
Just outside the breakroom door, each man stood on a precise scale to measure his weight while a researcher took his temperature, and the worker had to answer questions about how he was feeling.
In a plant where workers grind, shape and snip sheet metal to build equipment for heating and air conditioning efficiency and other purposes, the men were also serving as test subjects to see how their bodies responded to the summer heat — when the factory floor is cooled with fans and, at times, when it isn't.
Researchers and company officials said the workers are part of a joint project to study worker heat stress that has been commissioned by NovelAire's sister company, Madison Air, and the University of California, Berkeley's Center for the Built Environment.
Often, air-conditioning large manufacturing spaces isn't cost effective or practical, so the research project is examining the cooling benefit of the fans at a price lower than the cost of AC, the researchers said.
"Anecdotally, we know, it's hot … and it gets hotter when you don't have fans, so they are providing the data to back up what advantage you get, and we can estimate our productivity and the gains we're able benefit from having these fans," said George Latour, NovelAire's director of operations.
Though small office spaces at NovelAire's two factory buildings have air conditioning, the workshop floors don't. Instead, they have about 35 fans, including oversize ceiling fans built by Big Ass Fans, another sister company of NovelAire and Madison Air.
The factory floors constitute 52,000 square feet, reach roughly two stories high and have several large bay doors that were opened to the midday skies on Thursday.
The impact of heat
Officials with Madison Air hope the study will provide them data for an information campaign aimed at the 95% of warehouses and factories that don't have fans or air conditioning.
But the joint company-university study also comes as increasing attention is being paid to the health risk from heat in the workplace, both indoor and outdoor, as the climate warms and heat waves have become more frequent.
In 2024, a National Oceanic and Atmospheric Administration analysis of weather data for 50 large U.S. cities, including Baton Rouge and New Orleans, found the number, intensity and frequency of heat waves and the duration of the season for heat waves all increased between 1961 and 2023.
A separate data review by Climate Central, a nonprofit climate change research group, found that for 84% of 239 locations examined in the United States, the number of days where the heat index was 90 degrees or greater had increased by an average of 10 between 1979 and 2022.
Glenda Anderson, a University of Sydney researcher working on the NovelAire project, said the study provides important real-world research on worker heat stress that is lacking in the scientific literature.
"As the world gets warmer, we need to make sure that we are protecting our workers," Anderson said.
Federal labor officials reported an average of nearly 3,390 heat-related worker injuries between 2011 and 2020 that led to missed days of work, though various analyses suggest that number is greatly underreported. Heat also leads to a few dozen deaths per year, federal data show.
Measuring sweat
Charlie Huizenga, a research specialist with the UC Berkeley center, said that during the current three-week study phase, the buildings' fans are being turned off for half the day and turned back on for the other half as researchers measure the conditions on the factory floor and in the workers who volunteered for the study.
The workers who are test subjects wear heart rate monitors in addition to doing the questionnaires and weigh-ins.
Huizenga said the collection of data is designed to figure out how much the workers are sweating, a signifier of heat stress, because sweating is the body's way of cooling down its core temperature.
Early data from the project have found workers have been losing as much as 4 pounds of sweat during the half-day when the fans are off — up to 8 pounds for a full day.
"So that's enough of a signal for us to measure with the scale, right? If we're tracking everything they're drinking, everything they're eating. Before and after they go to the bathroom, we weigh them, so the only other thing coming in and out of them is the sweat, so that's how we can estimate that. Yeah, so it's a lot," Huizenga said.
He said early data from this past week have shown that running the fans appears cut that sweat loss significantly, though it was too soon provide hard figures, Huizenga said.
Huizenga pointed out that fans don't cool the air but increase the evaporation of sweat, the physical mechanism that cools body temperature.
Though some indicators suggest fans lose effectiveness at around 95 degrees, the surface temperature of skin, Huizenga said his work is showing the threshold is probably closer to 104 degrees, which is similar, if a bit higher, than other published research.
'You can do more'
Fred Agbulu, 56, of Baton Rouge, a supervisor at NovelAire who has worked for the company for 17 years, said he and his coworkers see the impact the fans make.
Several of them were hesitant initially to do the study, he said, because they already knew how the fans have helped since they were installed about four years ago and didn't want them to be turned off.
"For me," Agbulu said, "I like experimenting. I wanted to see actually what the difference is and … it showed me it's a big difference. It's a big difference."
He said it is no surprise to him that workers could be losing up to 8 pounds of sweat with the fans off all day based on how wet his clothes have been when the fans were turned off. As a floor supervisor, he said he can see the difference in productivity in himself and others by the end of the day.
"So, with the fans, you can do more," Agbulu said.
Amid petitions from public advocacy groups and state attorneys general, the U.S. Occupational Safety and Health Administration under then President Joe Biden began steps in 2021 to create new rules for a wide swath of businesses to protect an estimated 150 million workers from the risk of heat stress.
The proposed rules have been opened to public hearings and several comment periods and remain in one under the Trump administration, which has moved quickly to unravel many Biden-era regulations to spur economic growth.
The heat rules have drawn tens of thousands of comments, including from industry, farming, road construction and others that want more flexibility on proposed temperature triggers that would require protective measures.
OSHA officials said the agency is waiting on a final comment period to end before deciding how to proceed.