I have to disagree with you on this. Here's my reason.In cold weather, you do lose more heat from your head because, unlike in the rest of the body, the blood vessels lack the ability to constrict. This is a mechanism to protect the most vital areas of the body, and also why your hands and feet get cold first.
According to the doctors, my migraines are caused by the constriction of blood vessels in my brain. This makes a lack of blood flow and oxygen. They then open all of a sudden, supplying a rush. Kind of like a dam opening up. This is what causes the migraine.
If they are unable to constrict, as you say, then how is it that my head is doing exactly that?
Not starting an argument, just stating that this is what all the zillions of tests I've had has shown.