The smoke that a person inhales when smoking a cigarette or cigar has a number of ingredients that negatively affect the body. These include tar, which is all of the particles in the smoke. Carbon monoxide and hydrogen cyanide are also ingredients that inhibit the body, particularly the lungs, from carrying out its normal processes. Finally, tobacco smoke contains chemicals known as "free radicals," which are chemicals that can lead to things like heart disease, strokes and heart attacks. Tobacco smoke also cotains a number of different metals including lead and arsenic.
Tobacco smoke gets into your lungs and can affect your circulatory system in a number of ways. It can raise both your blood pressure and your heart rate as well as tighten your blood vessels. The tightening or constricting of your blood vessels in particular can result in a loss of overall skin temperature. An important job of your circulatory system is to carry oxygen all throughout the body via your blood. Smoking can result in less oxygen getting into your blood which will ultimately result in less oxygen getting to important parts of your body like your hands and feet.
The ingredients in tobacco smoke can cause your blood to become stickier than normal, which can make it flow through your veins and arteries more difficultly and lead to blood clots. Smoke can also cause the build-up of fat on your arteries which can ultimately lead to irreparable artery damage. Smoking in general causes the flow of blood to be reduced all throughout your body which can lead to loss of circulation and numbness in places like fingers and toes. All of this can lead to things like cancer as well as heart attacks and strokes due to your body simply not being able to operate in the way that it normally would.