" A person who is low-spirited or inharmonious will contract a cold; a happy, fearless person will be immune to germs. For example, a woman goes out in cold weather in evening clothes - lightly clad - but is quite comfortable, for she feels she is looking well and is filled with anticipation for a happy evening. If the same woman is dressed in an unbecoming gown or in a bad humor, she will come back complaining of a cold and discomfort and have a cough the next day. A harmonious person is never vibrating at the same rate as a germ. "
― Florence Scovel Shinn , The Magic Path of Intuition