What might help to deal with Reynaud’s disease?

@bajjerfan im sorry to hear that you’re having to deal with CREST syndrome. I looked it up and it certainly doesn’t seem pleasant. It doesn’t appear that I have the symptoms that would fit with CREST, though.

I used to suffer from blood loss in my extremities, and this was not good as an army officer in the Canadian Armed Forces. I can recall bitter times stamping my feet while waiting my turn on winter-time firing ranges to qualify on my series of small arms each year (a requisite form of annual 'refresher' training where we relearned any drills about weapons, went to the gas chamber to verify that our personal kit and gas mask were in good order, took a first aid refresher, etc).

The obvious is to wear some kind of covering. No, not necessarily on your hands....on your head. The Peruvian aphorism goes, 'When your toes are cold, put a hat on.' Gloves can work, of course, and better footwear or socks. One thing that helped me was doing hard work with my hands and building strong arms. The thing that generates heat in the body are the zillions of mitochondria. They are found in abundance in musculature.....so build it! Crumple paper or use grip-strengthening devices to build bigger hands with more blood supply and more mitochondria. Playing piano is good for the grip.

There is also that old urging that parents use, or used to before hours on digital devices became a thing, to go for a brisk walk or to run around the block once or twice. I used to tuck the kids in bed and then load our vehicle with astronomical gear, including a large and heavy telescope and its mount and tripod. I would drive out west of Winnipeg (AKA 'winterpeg), Manitoba, and then erect the scope and let it cool to ambient over the next 30 minutes (important to get good images because a warm scope has air currents inside that cause 'pluming', which seriously degrades any images...like heat waves on pavement). Well, mid-January on the Canadian prairie, at -26C, near 2300 hrs, and standing around for 30 minutes....you can imagine it wasn't long before I began to get chilled (down-filled 3/4 length parka with hood, lambskin lined helmet, lined cowhide mittens with hand warmers in the bottoms, and Sorel mukluks on my feet rated for -70). I had to move. So, I'd start out at a walk, increase the pace, and then break into a run that must have looked hilarious in all that gear. But by the time I got back to the scope, puffing and steaming (not sweating!!!!!), I was good for the next half hour and the scope was almost ready.

Essentially, you do what ya gotta do!!