In recent years, by prevailing of air cooling and heating conditioners and increasing of heat insulated and airtight buildings, drying of indoor circumstances has advanced. Such drying has given various influences to a skin or mucous membrane, and caused skin troubles as wrinkles or itching, fatigue of the eyes or dry eye. For protecting the face and eyes of the human living organism from the drying, a mist bath (steam bath) is useful, giving moderate moisture and bathing effects to diseased parts.
By the way, it has conventionally been known that carbon dioxide (carbonic acid anhydride: CO2) has both properties of being not only soluble in water (water-soluble) but also soluble in fat (fat-soluble) and, therefore, by only contacting the skin and mucous membrane of the living organism as being mixed with water and fat, carbon dioxide penetrates under a subcutaneous layer and expands blood vessels around the parts of penetrated carbon dioxide, and it works to improve the blood circulation. Owing to this action of accelerating the blood circulation, it displays various physiological effects such as dropping of blood pressure, improving of metabolism or accelerating to remove pain substance or waste product. Further, it has also anti-inflammation and anti-bacterial. Therefore, carbon dioxide has recently been given attentions also from viewpoints of improving health or beauty other than the purpose of medical cares.
Carbon dioxide in the tissue of the living organism works to release oxygen having been carried in combination with hemoglobin in a red blood cell. Around parts at a high density of carbon dioxide, the red blood cell releases more oxygen. Thus, supply of oxygen to cells by the red blood cell is mainly controlled by carbon dioxide. In short, being without carbon dioxide, hemoglobin remains as having been combined with oxygen and the cell becomes unable to receive oxygen. As is seen, carbon dioxide seems to be waste products resulted from action of the cell, however, it plays in fact very important roles in the living organism.
Further, recently, oxygen of the high density has also widely been known as effective in activity of metabolism, acceleration of blood circulation, fatigue recovery, or stability of blood pressure. Other than them, oxygen has effects of disinfection or sterilization by oxidation.