Decades ago an Army Sgt. told me best way to keep hands warm was to layer like this:
Silk glove
Wool glove
Leather glove
I remembered that advice and tried it.
Hands still got cold in 20 mins.
Started cooking my leather gloves on the muffler too often....which helped only when I stopped...
and can melt the stitching:-)
Battery gloves opened up winter riding for me!
Stig