Is true that taking very cold drinks after a night of heavy boozing causes one to shiver involuntarily? James Dear James, Alcohol causes the blood vessels to dilate slightly, which causes the flushing of face, after heavy drinking. However, if one drinks very cold water or juices, the morning after shivering occurs. Slight shivering can also occur after drinking cold fluids, even without taking alcohol, the night before. Water forms almost 70 per cent of the body’s interior. Fluids consumed become part of this liquid state of body. Blood flowing is normally warm and at body temperature. Sudden even slight fall in temperature of the water inside causes blood to thicken. The blood vessels contract to conserve heat and provide warmth to the body. This result s in shivering. As such drinking alcohol is also not healthy. Experts of naturopathy even advise against taking very cold water or any fluids, claiming that it is not healthy in the long run.