Get cold hands, but hate wearing gloves? Then there might soon be a technology that can help you. The US Army is developing an arm heater that allows people to go glove-free in freezing conditions, helping them to carry out mechanical repairs or first aid.
Gloves can keep your hands at a comfortable temperature, but they often reduce dexterity. Take off your gloves, though, and numbing cold has an equally detrimental effect on your fine motor skills, as well as being extremely uncomfortable.
John Castellani and his team at the US Army Research Institute of Environmental Medicine in Massachusetts are attempting to solve the problem with a pair of electrically heated armbands worn around the forearms.
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Castellani says much of the problem is due to the body shutting down blood flow to peripheral areas. Keeping the forearms warm counteracts this, he says.
A showed that heating the torso also keeps the hands warm, but that approach requires too much power for a portable device. Castellani鈥檚 team has found that warming just the forearm with a battery-powered device improves both finger temperature and the ability in tasks requiring manual skill, such as putting pegs in a peg board. In tests, their device reduced dexterity loss by 50 per cent and finger strength loss by 90 per cent compared with wearing no gloves at 0.5掳C.
The electric forearm heater helps by a combination of delivering warmer blood to the fingers and reducing blood vessel constriction. Even if the wearer can鈥檛 go gloveless, it could allow them to wear thin gloves, rather than thick mittens, for precise tasks.
鈥淎 comfortable person is a person that can do their job,鈥� says Castellani. 鈥淐omfort is important.鈥�
Castellani says that further engineering development will turn the prototype into something lighter, more rugged and more efficient for production. The goal is a device that will increase finger strength and dexterity during 4 hours of exposure to freezing air.
He expects a forearm heater to be fielded by the US Army in the next two or three years, with commercial versions following shortly afterwards.
