MOREHEAD, Ky. (AP) — To harvest tomatoes, peppers and cucumbers, to clip herbs, to prune and propagate succulents, people work in oppressive heat and humidity. Some wring out shirts soaked with sweat.

Some contend with headaches, dizziness and nausea. Some collapse. Some hover on the brink of exhaustion, backs straining, breathing heavily.

Many do so not out in farm fields, but indoors – under the roofs of greenhouses. In structures designed to control the growing environment of plants, some workers described humidity with temperatures sometimes soaring past 100 degrees Fahrenheit (nearly 38 degrees Celsius). “The heat is unbearable and the humidity equally so,” said Estela Martinez, speaking in Spanish of the six years she worked in a nursery in Florida.

“I lost too much weight because my T-shirts were coming out soaked, soaked from the heat inside.” The number of greenhouse and nursery workers has increased by over 16,000 people in recent years, according to data from the latest U.S.

agricultural census. Some work in conventional operations like commercial nurseries, others The data, along with stories of 10 current and former greenhouse workers approached by The Associated Press, shows a growing population of workers who are increasingly vulnerable to heat-related illnesses, injuries and death as global temperatures rise and greenhouses become more popular. They work in a gray area – they’re both indoor and agricultural workers, but are not always included .