News | Aug 22, 2019

US Army invention ‘tricks’ body into sending warm blood to cold fingers

Patent-pending Personal Heating Dexterity Device offers improved capabilities and safety of military or recreational users

Soldiers from the 10th Special Forces Group ski in Montana in 2017.

Craig Cantrell/Army

Since at least Gen. George Washington’s long winter at Valley Forge, the U.S. Army has been looking for ways to keep G.I. Joe’s fingers warm in cold weather. New technology promises to help.

To be sure, the Army will likely never abandon trigger-finger mittens. In fact, it began buying thousands of sets of the new and improved Cold Weather Glove System in June. But soldiers frequently have to pull off their gloves to do things like program the radio, load ammunition, and shoot.

So, research physiologist John Castellani, the Army’s cold-weather expert, has been experimenting with small heating pads, placing them on the cheeks and forehead of cold soldiers, which stimulates the trigeminal nerve area and sends blood flowing to the hands.

As the blood heads into the frosty fingers, it’s temperature is raised by additional heat pads on the soldier’s forearms.

Dr. John Castellani, a cold-weather expert at the U.S. Army Research Institute of Environmental Medicine, demonstrates a prototype of the Personal Hand Dexterity Device. At critical moments, soldiers’ cold hands can prevent accurate rifle fires. (via USARIEM Facebook)

“One of the biggest issues for soldiers operating in a cold environment is the loss of hand function and dexterity,” Castellani said. “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.”

Along with co-inventor Timothy Driscoll, Castellani has invented the “Personal Heating Dexterity Device.” The Army’s patent application was first made public on August 15 and explains that the heating pads are connected to a set-point controller.

“Heating the face exploits a physiological reflex and tricks the body into believing it is warm rather than cold and increases the blood flow to the fingers,” the patent applications states. “By combining facial and forearm heating, the invention gives bare-handed individuals the increased manual dexterity and thermal comfort needed in cold weather environments.”

According to the Army, the research team is working to advance the prototype, making the device more portable and user-friendly.

In coordination with the Army’s technology transfer program, TechLink helps private companies evaluate the commercial potential of Army inventions and negotiate mutually beneficial license agreements.

Quinton King, senior technology manager at TechLink, is the point of contact for interested parties.

King is contact with the Army’s intellectual property experts and has reviewed the new heating device, noting the tech’s obvious dual-uses for outdoor recreationist like hunters and skiers and industrial workers in cold weather environments.

“Agile performance in cold weather regions requires preparation and training,” King said. “But the Army research community can provide additional advantages. Through technology transfer, non-military users could also benefit.”


Companies interested in evaluating the technology, discussing the business opportunity, and Army patent licensing can contact Quinton King and quinton.king@montana.edu or 406-994-7795.