This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
The vapor of water, in the form of the steam-bath, lamp-bath, hot wet-packing, or Russian bath may be used to accomplish still more thoroughly the same objects as those to be expected from the warm or hot bath. In one good form of vapor-bath, the patient sits unclothed in a chamber to which steam is admitted, but the head is outside, covered with a cold cloth. In a less complete, but more portable form, the patient sits on a chair covered with blankets, while steam is generated by a spirit-lamp placed under a pan of water: or a somewhat similar result may be obtained by dropping freshly burned lime into a bucket of water under the chair, or a heated brick into hot water; or if the patient be too weak to rise, steam may be conducted under the bed-clothes raised by hoops; or a heated brick, wrapped in moistened cloths and flannels, laid near each limb. The most complete form of such bath is, however, the Russian bath, which is given in a closed chamber filled with steam. On first entering the bath there is often a disagreeable sensation of heat and burning in the skin, the pulse becomes quick, and respiration uneasy; sometimes there is a feeling of pressure on the eyes, heaviness in the head, and dizziness; but these symptoms soon pass away, and the respiration becomes more natural and deeper, the blood finds easier access throughout the body, the skin soon gets red and moist, and the patient comfortable.
Eulenburg states that the steam-bath raises the body temperature to a very appreciable degree; on an average a steam-bath of 41° to 42° C, by 1 1/4 to 1 1/2 degree C. ("Real-Encyclopaedia," 1880, i., p. 708).