Research on extreme heat and outdoor laborers is still a growing field, despite the number of people working in these environments daily, said Cecilia Kaufman, director of the institute’s occupational safety and one of the study’s leads.
New study finds key way for outdoor workers to stay cooler in Connecticut heat
Published: July 19, 2025
This article was originally published by Greenwich Time
Connecticut is experiencing some of its hottest summers on record in recent years, leaving residents to bear the brunt of a warming climate.
This trend can be perilous for the hundreds of people who work outdoors, such as construction workers and farmhands. Nationally, an average of 34 people a year have died in the workplace because of heat exposure from 1992 to 2022, according to the Environmental Protection Agency.
However, researchers at the University of Connecticut found that one easy solution to help employees working in extreme heat stay cool is to wear more clothing with moisture-wicking technology.
The study, conducted through the university’s Korey Stringer Institute, found that participants who had access to these body-cooling garments, such as hats, sleeves, and neck gaiters, had lower core body temperatures and were more productive overall.
“We have tons of research in the athletic setting and in the military setting. But, I think, for a long time, that this general population was pushed to the side and not thought of as a potential population that could be affected by the heat,” she said.
Connecticut does not have labor laws or regulations related to excessive heat in the construction industry, according to Eva Zymaris, a spokesperson for the state Department of Transportation.
However, she noted that occupational heat stress and hazards do fall under the federal Occupational Safety and Health Administration regulations, which address known dangers in the workplace. The state adheres to these standards, especially for road maintenance crews, making adjustments to prioritize health and safety.
“We focus on employee education on the heat index, preventing and knowing the signs of heat-related illnesses (and how to respond), and prioritizing hydration, frequent breaks, cooling/shade, and making adjustments to work schedules and productivity expectations when necessary,” said Zymaris in an email interview.
The idea to study the effects of body-cooling garments builds on the results of 2022 KSI research, which tested different strategies that outdoor workers can use to mitigate heat, including providing shade, offering plenty of water, and wearing body-cooling garments. Kaufman said the goal of that first study was to see how adding protective layers and strategies could influence physiological responses and productivity. Still, it also raised questions about the effectiveness of body-cooling garments on their own.
A total of 14 men and women participated in the study, who wore garments from MISSION, a body-cooling clothing brand that also supplied garments for the 2022 study.
Kaufman said she and the other researchers would soak hats with neck flaps, neck gaiters, and sun sleeves in ice water and wring them out every 20 minutes. Then, while wearing the soaked clothes, the participants would perform aspects of manual labor, such as lifting boxes, under a solar radiation lamp that simulated clear, sunny skies. They’d then take the participants’ internal core temperature during the last 30 minutes of the trial to project what their temperature could be like at the end of an eight-hour shift. The control group, Kaufman said, performed the same tasks under the same conditions, but were wearing simple long-sleeve shirts.
Participants wearing the cooling garments were, on average, one degree Fahrenheit cooler and more productive than those in the control group, who were projected to be at high risk of developing hyperthermia or other heat-related injuries by the end of the shift, according to the study’s conclusion.
When projected across an eight-hour shift, Kaufman said participants wearing the cooling gear spent 18 fewer minutes above the maximum recommended core body temperature for workers, indicating that they were able to maintain a lower core body temperature throughout the day compared to those without the equipment. The findings were published in the American Journal of Industrial Medicine earlier in July.
“That just means that they could essentially work longer and… there was reported lower ratings of perceived exertion, fatigue, thermal discomfort in that cooling trial,” Kaufman said.
The next steps in their research, Kaufman said, would be to take the findings out of the laboratory setting and apply them to the real world. She also hopes the study can inspire other research projects on employees who work outside and what can be done to protect them on a warming planet better.
“We know that water, rest and shade have been kind of the emphasis in this space, but there’s a lot of ideas of body-cooling garments, and literature about what does work, what doesn’t, what properties of those garments work, and just how we can utilize that,” she said.