You probably have poor circulation in the skin of your hands. Blood circulation in the skin depends upon the dilatation and constriction of the skin arteries. When arteries are dilated, the blood circulation in the skin is greater and the hands are warmer. When the arteries are constricted, the circulation is poorer and the hands are colder. In normal occasions when body is exposed to warm, the skin arteries should be dilated for proper body cooling. When exposed to cold, the skin arteries are constricted to decrease peripheral circulation, thereby saving body warmth. In your case, it seems that these vasomotor reflexes are disturbed and the vasoconstriction in the skin dominates all the time. Vasoconstriction is controlled by the vegetative nervous system, or more precisely its part, "sympaticus". When the sympaticus is activated, it causes vasoconstriction of the arteries. The center of the vegetative nervous system is the hypothalamus. Many events in the body can influence the hypothalamus, including anxiety. I recommend you visit your doctor to verify if your hands are really cold and then follow up on her/his recommendations.