An Encyclopaedia of Domestic Economy, 1844
The shower bath, notwithstanding the abuse in its application and the consequent injury, is, when properly applied, one of the best baths ever employed… Begin with the water tepid, then change to cool, followed by a dash of cold, is the best plan for most bathers. Arrange the water at the right temperature, then let it fall first upon the hands and arms, rubbing them vigorously; then upon the feet and legs, then the neck, back and chest, rubbing each part while the water falls upon it; then turning the body, alternately exposing different parts to the falling shower for two or three minutes… As a general rule the cold water should not fall on the top of the head, nor even the tepid water, if the hair is long and heavy; but if it is short, and the bather in good health, it is a great luxury to let the tepid or cool water come trickling down over the head, face and entire body… The shower bath… is useful for cleanliness, for increasing the external circulation, and for removing internal congestion and inflammation… for those in a vigorous state of health it is a decided luxury to take it, cold, as a regular morning bath.
E. P. Miller, “How to Bathe,” Herald of Health
Nothing says “great luxury” like two or three minutes of cold water on your head.