To keep feet warm: A few years ago my crew gave me Thermosoles.com ($100). Worn inside any shoe that fits, they work great. They last 8+ hours and control foot temp to 98F, so never too hot or too cold, and saves (LiPo) batter power. If it's really cold I wear them inside felt boot liners for Sorel boots, but w/o the boots. The felt boot liners are not too big, flexible and very warm. Good felts have a thin leather sole, which is nice if the ground is damp. I keep walking shoes in the glider storage area for before and after the flight.
~Bruce