There are pros and cons to finding the right pair of winter gloves.
The challenge is to sacrifice warm hands or dexterous fingers. For civilians, the choice between form and function could limit the ability to text friends in freezing temperatures. However, for soldiers, losing hand function in the cold can negatively impact performance, survivability, and lethality.
One of the most important problems for war fighters and people in general is that exposure to cold severely impairs hand function.
“That’s because in cold environments, the body reduces blood flow to the periphery to protect core temperature,” said Dr. John Castellani of the US Army Environmental Medicine Research Institute. “So areas like hands and feet see less blood flow and therefore skin temperature goes down.”
Army researchers like Castellani have spent the last 80 years developing technology for various body parts to increase blood flow in the hands without impeding hand movement.
Castellani has spent decades studying the effects of cold weather on soldier health and performance. Together with other scientists, he has developed a new device that warms hands and fingers in cold weather without gloves.
The Personal Heating Dexterity Device, or PHD2, helps prevent loss of hand function in the cold.
In the hands, manual dexterity deteriorates as skin temperature decreases. The purpose of the PHD2, Castellani said, is to increase hand and finger temperature by delivering external heat to the forearms, which is absorbed and eventually increases the temperature of the hands and fingers.
“This increase in temperature will improve dexterity,” Castellani said.
Cold weather environments can affect soldier performance in a variety of ways. It can affect both aerobic and anaerobic performance, muscle strength and endurance, cognition, fluid balance and manual dexterity, Castellani said.
Castellani and his team sought to resolve the loss of dexterity, which is critical to many tasks such as loading ammunition, handling equipment and technology, and treating injured soldiers.
“Gloves themselves can reduce manual dexterity by 50 to 70%. We wondered if we could find a solution that would allow a person to have warm hands even when working barehanded, so that dexterity is maintained,” said Castellani.
As for feet, they are harder to keep warm.
“It could have to do with the fact that we humans are bipedal/erect, which affects how the nervous system controls blood flow,” Castellani said. “We’re not sure that the same concept – heating the calf – will have the same effect. We would like to pursue this further.”
Researchers recently came back with a very early field prototype to get feedback from troops at Arctic Eagle, a joint exercise in Alaska involving more than 900 Air and Army National Guard personnel from 15 states, to see what they came up with think the concept and what they do would like to see in future versions.
“We have to develop prototypes with advanced materials and power supplies so that they fit perfectly and weigh very little,” said Castellani. “Soldiers are already burdened with carrying too much weight. So that’s what we’re going to do over the next few years.”
The Army hopes to field an operational PHD2 by 2026-2028.
https://nypost.com/2022/03/05/army-develops-high-tech-solution-to-keep-hands-warm-without-gloves/ Army develops high-tech solution to keep hands warm without gloves