The problem for me, and likely many with Reynaud's, is that it isn't the palm or back of the hand that needs heat. It's the digits themselves that lose circulation and therefore warmth. I don't know if heated gloves work that well for the fingers and thumbs, but then I've never tried any. Perhaps there are some that warm the fingers as well.
Heated motorcycle gloves do in fact heat the fingers and thumb. I have some being a Harley rider and use them quite often in the cold weather. Be sure to get a good brand and newer model for the best results.
Gerbing or Warm-n-Safe are a couple of the better ones. But be ready they are not cheap. You can pay a couple hundred dollars for a good Hybrid pair.