The fair sex is often affected by the fact that freeze in the hands and feet, regardless of the weather. If it can not warm the extremities with no gloves or with the help of wool socks. The problem does not save even a hot tub. Hands and feet are warm in the morning after waking up. Now the reason for this physiological phenomenon explained.
Cold hands and feet, as it turned out, this is a consequence of the action of hormones. Beneath the skin thermo-receptor cells (at a distance of less than one millimeter) are made to feel temperature changes. The skin feels comfortable, usually due to the pumping of blood through the smallest blood vessels - capillaries.
The body temperature of a woman during the menstrual cycle changes, as there are jumps and falling estrogen levels. Thermo-receptors block the capillaries, detecting cold that preventing normal blood flow and heat into vital organs such as the heart, lungs, etc. This process is called vasoconstriction.
The interesting thing is that when a woman experiences a cold, the amount of blood entering the limb can not be more than 0.02 liters per minute, while the top speed of two to three liters per minute. So of course women "donate" their dose of blood in favor of important internal organs. That’s why cold hands turn white and become blue, and the survivors in extremely cold conditions, by all means get frostbite and hands, and feet.