This is likely due to peripheral vasoconstriction. This happens in order for the body to retain heat longer in order to protect the body from hypothermia. The skin would act as an insulator of the organs and water. Also, when this happens, it would allow more of the oxygen to be transported to the oxygen sensitive organs like the brain and the heart.
The heart itself needs blood and nutrients to work properly and gets its share of blood supply from coronary arteries. Coronary heart diseases are linked to coronary arteries. The diseases of coronary arteries are very dangerous; coronary artery diseases like atherosclerosis may cause heart attack.
In the lungs, oxygen is put into the blood and carbon dioxide is taken out of the blood during the process of breathing. After the blood gets oxygen in the lungs, it is called oxygen-rich blood.
A warm soft place to sleep and a quiet environment. Maybe certain music can be a factor too.
