People who smoke often have cold hands and feet. What might explain this condition in terms of blood flow?
Nicotine is a stimulant, and has a vasoconstrictive effect; which means that that the blood vessels become narrower in response to it, and less blood passes through them. This effect is made most prominent when a vasodilatory action is applied to the tiny capillaries in the hands, feet and other extremities, such as the nose and ears.
As you may well know, the role of blood is not only to supply the body with oxygen and nutrients, but also has an important role of keeping the body warm.
When the circulation of blood to an area is reduced, the temperature of the skin/tissue in those areas is also decreased.