Previous research by the U.S. Army Research Institute of Environmental Medicine has found that soldiers operating in cold weather can either have warm hands or hands capable of operating critical equipment. Thick gloves can reduce soldiers’ touch sensation and fine-motor dexterity by 50 to 75 percent, according to 2018 research for the institute.

Scientists at the institute have developed a device that can keep soldiers’ hands warm without gloves, reports the Military Times.

Earlier researchers looked at developing a device to warm soldiers’ torsos, but found it would require a heavy power source to be carried with it. Instead, they looked for a solution closer to the hands.

To develop the devices, researchers crafted a prototype of forearm devices resembling heating pads. Volunteers tested the prototypes by sitting for two hours with their hands uncovered in a special room researchers set at 32 degrees, according to an Army press release.

The institute’s ending result is a “Personal Heating Dexterity Device.” The battery-powered heater warms up the wearer’s arm, allowing blood to flow to their fingers while improving their dexterity and warmth.

“The loss of hand dexterity can occur because the body’s natural reaction to more frigid temperatures is to decrease blood flow to the hands and feet,” Dr. John Castellani, a researcher at the institute said in a press release last year. “The body sends that blood to protect and warm the core, where major organs are located. The problem is that warfighters need hand dexterity for many military-relevant tasks, including shooting, handling equipment and treating injured Soldiers.”

Currently, the forearm device is in its prototype phase and will be field tested later this month with Alaska National Guard troops during the Arctic Eagle 2022 military exercise, reports the Times. After getting tested, they’ll be further developed and be present on the battlefield.

Since developing the device, researchers have looked at other ways to keep soldiers warm in cold conditions, which put them at risk of frostnip and frostbite. Exposure to the cold can be a problem for soldiers. According to an article published on the Army’s website last year, the number of hospitalization days due to cold weather in World War II and Korean War was more than 3 million.

Castellani told the Times that Army researchers are now looking into developing a similar foot-warming device within the next three to five years.