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 application of water to the treatment of these disorders is one of the most important results of modern therapeutics - or rather of a revival of, and improvement upon, older ideas, for it is not wholly modern. Wright and Currie adopted it in 1786-1796, using cold effusion, i.e., dashing several buckets of water over the patient when stripped. The latter physician records an epidemic of typhus fever affecting 58 soldiers, most of them severely: 56 were treated by cold salt-water effusion, and all recovered; the other 2, considered too weak for this treatment, were the only fatal cases. He traced an evening exacerbation, and insisted on the importance of using the remedy during this access: or at least during a period of great heat, and not during a rigor, nor during a profuse perspiration ("Medical Reports on the Effects of Water," London, 1798). His method of treatment, although valuable and successful, was too harsh for ordinary use; but soon after his observations, Giannini, of Milan, advocated immersion in cold water for two to fifteen minutes in all forms of fever (especially intermittent, petechial, rheumatic, and scarlet fevers); he drew up very judicious rules for practice, and he had very good success, but he objected to the use of ice ("Della natura delle feb-bri," Milano, 1805). Frohlich (1822) was one of the first to regulate his practice of cold or tepid bathing by the thermometer. An account of his and many other earlier observations has been given by Fleury ("Traite d'Hydrotherapie," Paris, 1866). In our own time, Ziemssen has improved upon the older methods, by his process of gently lowering the patient (with a sheet) into a bath at a temperature of about 98° F., and then gradually cooling it by addition of cold water or ice to 80° or 72° F., or even lower, according to the effect produced; this should be noted by a thermometer (placed in the rectum if possible). When a distinct reduction of the fever heat is evident (it may be in five minutes or in thirty), the patient is dried, and laid again in bed, and the process may be repeated two to six times daily. A less complete mode of attaining a similar result is by cold compresses to the trunk, ice-bags to the spine and other parts, injections of iced water into the rectum, or the wet-sheet pack. All such applications, valuable as they are, must be carefully watched: they depress the circulation, sometimes extremely, and may need, after their use, stimulants internally, and hot cloths and bottles externally, in order to relieve too-cold extremities, blue lips, and tendency to collapse. The bath generally used in Germany has a temperature of about 70° F., or somewhat lower, and the patient is kept in it for about ten minutes, but very weak subjects only from five to seven minutes. Ziemssen now uses this bath, I believe, more frequently than the gradually cooled one, mostly mentioned with his name.