Warm & Safe who make First Gear electric liners also make gloves. I purchased them last week and tried them on 2 different nights with same temps 37 degrees: the night before the gloves arrived, my palms were toasty bcos of the heated grips, which I'd have on high to keep the rest of my mits warm. The second night, I kept the grips on 50% and the rest of my hands were comfortable. Honestly I cannot say that I felt the impact of the glove liners. There was no sensation of the coils, but my hands were discernibly more comfortable with a lower heated grip setting.I have no heated gear but a good pair of heated gloves would be first on my list, I don't know of any that get great reviews.
I do wear a cooling vest underneath a mesh Firstgear Adv jacket often in the summer when temps are 100+, I crossed the Mojave several times this past summer with temps in the 120F range and I don;t think that I could have made it without the vest, I'd make stops and use water hose (when I could find one) to literally soak myself and in less than hour even my socks and underwear were dry.