Polymers Make These Gloves Hot Electrically heated gloves can save your fingers in extreme cold, but there are two challenges in making them. One is getting the heat evenly distributed. The other is preserving battery power so they stay hot as long you need. The glove company Chaval claims to have solved those problems by using a polymer film instead of wires. The polymer delivers power specifically to the coldest spots to preserve battery power. The company claims the gloves will stay warm up to three times longer than conventional gloves that use electrical wires for heating elements and are set to a similar temperature. The problem with conventional electric heating elements is they heat uniformly. That sounds good, but if part of your hand is exposed to wind - say you are on a snowmobile - one section of the glove can get cold, while the parts tucked around the grips and out of the wind get too warm. All the while, the gloves draw power steadily. The polymer in the Chaval Response XRT gloves becomes denser when it gets cold. The denser it gets, the more conductive it gets. The more conductive spots then automatically draw more power and get hotter. That also lets the battery dole out power at a variable rate, which is more miserly than the consistent draw of conventional battery-powered gloves. In a test, I wore the Chaval gloves while motorcycling in 40 degree weather. The warmth was more uneven than I would have liked. My fingertips were chilled while my knuckles were overheated. That may be due in part to the way the glove pulls tight across the knuckles when gripping the handle bar. I got used to it. The company said it was looking into a design improvement that would provide more heat to the fingertips. The gloves do seem to deliver on the extended battery life. I have ridden with the gloves twice, totaling more than two hours of saddle time, without recharging. In theory, I have about four more hours coming to me. Though the gloves are a bit bulky, I could still operate turn signals and smaller controls with some effort. The gloves are constructed of weather-treated leather outers with a microfiber fleece liner. The power source is a built-in lithium ion-battery. You can send them back for new batteries (for a fee) when needed, usually after a few years. The Response XRT gloves are available for $390 direct from Chaval online only.