US Army researchers will test a hand-warming device during the Arctic Eagle 2022 exercise, beginning later this month in Alaska.

The battery-powered Personal Heating Dexterity Device heats the forearm, causing blood to flow into the fingers and increasing hand dexterity, researchers from the US Army Research Institute of Environmental Medicine (USARIEM) explained.

“One of the biggest issues for soldiers operating in a cold environment is the loss of hand function and dexterity,” USARIEM cold research team principal investigator Dr. John Castellani said. 

A soldier with the 4th Infantry Brigade Combat Team (Airborne), 25th Infantry Division, at Joint Base Elmendorf–Richardson, Alaska, in January 2018. Image: Alejandro Peña/ US Air Force

Gloves Reduce Dexterity Up to 75 Percent

“Thick gloves can reduce soldiers’ touch sensation and can decrease fine-motor dexterity by 50 to 75 percent. As a result, soldiers tend to remove their gloves when they need to use their fingers. Unfortunately, this causes blood flow to decrease in the hands, also impairing movement.

“This is a primary concern because hand function and dexterity are important for many tasks, such as loading ammunition, handling equipment and technology, and treating injured soldiers.”

During testing, researchers put forearm and facial warming device prototypes resembling heating pads on eight volunteers for two hours in a climate-controlled chamber. 

The bare-handed volunteers wore cold-weather dress at a temperature of 32°F (0°C) and loaded “ammunition into an M16 cartridge and [took] the Purdue Pegboard Test, which involved picking up and moving small pegs into sockets.”

A soldier assigned to the 1st Squadron, 152nd Cavalry Regiment, 76th Infantry Brigade Combat Team, 38th Infantry Division, Indiana Army National Guard, at Lešť military training center, Slovakia, Nov. 1, 2019. Image: Senior Airman Jonathan W. Padish/ US Air National Guard

In-House Testing

“We found that just heating the forearms worked,” Castellani revealed

“Heating the face by itself was not effective, and heating the face and forearms together was not a significant improvement. We also found that turning on the device after the fingers had cooled significantly was just as effective as keeping it on the entire time.”

See also  Ricardo Defense to Supply Safety-Critical Systems to Retrofit US Army Humvees

Investigators are reportedly also working on a foot-warming device and testing the “effect of a cocoa-based flavanol supplement in cold conditions.”

Previous studies have shown that flavanol can help improve blood flow. USARIEM research will focus on whether it can increase blood flow to the hands and fingers.