In the late 18th and early 19th Centuries, people believed cold baths in the morning staved off colds, flu, etc, and hardened the body to illness generally. I can't locate the source, but apparently there is some truth to the "hardening" idea, though it just may be that people who have the gumption to do this generally take better care of themselves. My granny (1889-1983) believed in cold baths first thing in the morning. I do a quick cold water rinse after my shower (not baths--not as much gumption as Gran!). I used to think the cold rinse was why I never had blemishes in my teen years, but who knows. Not so bad in summer, but you got to steel yourself in the winter.
This time, like all times, is a very good one, if we but know what to do with it. Ralph Waldo Emerson
Any given day you are surrounded by 10,000 idiots. Lao Tsu, founder of Taoism