White spots on her leg when they are cold?

My sister sometimes gets white spots on her legs when she is cold. We are both white girls and our complexions are pretty party. But even when she gets suntan legs it sometimes happens. They stir away when she tans or shes out in the sun and when she warm them up... why does this happene?White spots on her leg when they are cold?
Mine do that too. Its no big deal. the blood get thicker in cold situations, which trade name the veins appear dark than the the parts that do not have vein in them. So the white blotches are be veins are not. That's why when her legs bring back warm again, and the blood thins out they are a all-inclusive color.
This indicates that she is having a circulation problem.
You see, when she is cold, her body react to protect her vital organs and smaller amount blood is sent to the extremities. This is why in extreme cold ethnic group get frostbite.
These white spots are due to the capillary closing off and smaller quantity blood getting to the surface area of her skin.
She may be diabetic, or anemic. Have her check next to her doctor. She may just stipulation to take vitamins next to iron.