The water of a cold bath should have a temperature of 40° to 60° Fahr. If employed for its tonic action, the patient should not remain in it longer than the period of complete reaction. The tepid bath has a temperature of from 85° to 95°, the warm, bath from 95° to 100° Fahr., and the hot bath from 100° to 106° Fahr. The duration of the stay in these will depend on the purpose to be accomplished, whether mere excitation of the circulation in the skin, diaphoresis, or muscular relaxation. In directing the warm and hot baths, it should not be forgotten that a diseased state of the cerebral arteries is a contraindication to their use.

The vapor of water in the form of the Russian bath, steam-bath, or warm or hot wet-packing, may be used to accomplish the same objects as those obtained by the warm or hot bath. Without entering unduly into the details, it will suffice to state that the Russian bath consists in the exposure of the body in suitable apartments to the vapor of hot water, at a temperature gradually increased from 95° to 110° Fahr. The bath should not, under ordinary circumstances, exceed fifteen minutes in duration. In order to overcome the relaxing and debilitating effects of the bath, the patient should either enter a cold bath or have cold water dashed over his body. This expedient, conjoined with friction of the surface, increases materially the good effects of the Russian bath. In the absence of special arrangements for giving the Russian bath, simple means will suffice. The patient may sit upon a low stool with a blanket pinned about his neck, and under this the vapor of water may be conducted. Or, if confined to bed, the patient may be placed on a gum-cloth, and the blanket may be elevated above him by hoops, arranged transversely, under which the vapor of water may be conveyed from an ordinary tea-kettle. Fresh lime is sometimes used to generate hot vapor. The patient is placed on a low stool and surrounded by a blanket. Some pieces of freshly burned lime are then dropped into a vessel of water placed under the blanket. The slacking of the lime causes great heat, and the consequent generation of a considerable quantity of watery vapor, which also carries up with it minute particles of lime. This proceeding is said to be especially efficacious in membranous croup and diphtheria.

Enveloping the body in cloths wrung out in hot water, or wrapping in a sheet which has been wrung out in hot water, and then covering with blankets, is a mode of applying moist heat which may be advantageously used. To various parts of the body, under the designation of "fomentations," warm and hot water applications are constantly used in domestic practice.