"If it's mild, then at home you can gradually re-warm the area by soaking it in a warm bath for 15 to 30 minutes and make sure the rest of you is warm, too, by drinking some warm fluids. If it's more serious, then you have to seek medical care. They'll do some of the same things such as warm soaks, but they'll also be able to give you warm IV fluids. They may give you oxygen if necessary. They also may give you a pain medication because, as the tissue gets reperfused, meaning the blood is perfusing again to the area, that can be super painful."