I am 67 and my fingers always get cold and I have been trying to find a glove to keep me warm. I have bought several of the top brands but nothing has worked. A few months ago I bought a Swaney 3 finger mitt and went to Maine for some -30 degree skiing. I tried silk liners with Zippo metal hand warmers, yes the ones you light, they will fit in the glove, but I was still cold.
The new little heat packs are very hot this year for some reason and I put them in the glove but that did not work either.
I was in Mud Sweat and Gears at Holiday Valley where I buy my Blizzards and I saw a pair of Auclair Deer Skin Mittens with Duck Down Installation. No fingers, a true mitten. Could not help myself and I paid $116. I wear a large but I bought the XL. Used merino wool thin liners and the little heat packs you buy and tried them at -7. For the first time this year my fingers were warm all day. In fact too warm, started to sweat so I removed the heat packs and all was good.