I have what I believe to be a mild case of Reynaud's - it affects only some of my fingers. For me the key is core temperature and carefully managing it. As long as my core temp is up my circulation to the extremities is good and though my hands may get a little cold the circulation doesn't shut down and they don't turn white. But if I let my core temp drop, say by not adding layers soon enough when I stop, then some fingers will go white and I have a hard time getting my hands warm again. And warmer gloves/mittens don't make much difference for me - it's all about having a good flow of warm blood from the core to the extremities. I never have any issues with my feet, but that's mostly because when I am in the snow I'm skiing, and my ski boots - plastic with thermo-moldable foam liners - are very warm. I'm having to learn to manage my clothing more carefully than I did before, because now I can't get away with what I used to be able to