From what you describe what might work better for you is something with more mass, like wool gloves when you need to do something with your hands, and heavy mitts with enough mass to hold heat for when you shove your hands back into them to warm you hands back up without just turning instantly just as cold as your hands. It would be good also to have a pouch/pockets in your jacket/sweater that go in right under the outer insulation to your skin layer, and you keep you overmitts there when you aren't wearing them, or when your hands are in them. Ideally they would just fit your mitts and still have a good seal with the outside when your hands and wrists are in them. Sometimes there is room in there for a canteen also, filled with hot tea. I have a 200wt fleece sweater with a great pouch, but haven't made zips or velcro flaps in my skin layer to match. Also I prefer a wool sweater and fleece pants, so I really need to add a pouch to my sweater. With a down jacket it would be sufficient to get in under the down and not the layers under, but I think a down 1/2 zip with a pouch would be better than a full zip. I think even with 'cold hands' its good to give them the practice of getting cold now and then and then warmed back up. The fingers and hands are supposed to vasoconstrict more significantly than any other part of the body, (except the gonads maybe). Something like 60% of the mass of fingers is blood volume, when not vasocontricted. I'm not saying people should let them freeze, but I think everyone should 'work' them, meaning let them get cold, then warm them back up again, let them get cold, then warm them back up. I think this is best when you have heavy mitts or deep pockets. You shouldn't need hand warmers. You should be able to let your blood do the work. Overmitt or pocket warmers are a good idea though. I think the overmitts or pockets need to be warm enough though to help trigger the blood to let it know its safe to flow back in. As a student I used to carry a hard boiled egg in each pocket heading back up the hill on cold mornings at UNB Fredericton. Walking everyday, a few -30F mornings each winter were pretty much guaranteed.