The more alcohol a person takes the colder he becomes.

If alcohol were good food would we expect this to be the case?
It is probably true that the alcohol does make a little heat, but at the same time it causes us to lose much more heat than it makes.

The outside of the body is not so warm as the inside.
This is because the warm blood in the blood-vessels of the skin is cooled more rapidly than the blood in the interior of the body.

The effect of alcohol is to cause the blood-vessels of the outside of the body to become much enlarged.

This is why the face becomes flushed.