An extremity-warming system developed for snipers and helicopter pilots may provide just what the cold-weather angler needs most: warm fingers. The system relies on a high-tech ring which transmits data to a vest that responds by raising the body’s core temperature. “‘When the trunk gets cold, it draws the heat from the extremities into the core. So what this thing is doing is the very opposite,’ Mr. Rodgers said. ‘When it notices that the hands are getting cold, it extends the heat into the core, which allows more to go back to the extremities. That’s kind of neat, actually.'” And it might actually remove the idea of threading size 22 flies in the snow from the realm of fantasy. Chris Lambie in the Halifax, Nova Scotia Chronicle Herald.