This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
The warm bath is in general less advantageous in the idiopathic fevers than the phlegmasiae. Still, it may be occasionally employed with advantage, especially in children, when symptoms of nervous irritation appear, as restlessness, wakefulness, muscular twitchings, and convulsions. in the form of lotion, as by sponging, warm water is frequently used in order to relax the skin and diminish heat, under circumstances which forbid or render imprudent the external use of cold water; as when the disease may be complicated by visceral inflammation, or there may be some chilliness, or, in parts of the surface, a disposition to perspiration.
In the form of pediluvium, the remedy is often useful, by calming restlessness, promoting sleep, and disposing to diaphoresis.
It is, however, internally that water proves most beneficial in fevers. Here it is used cold; and the temperature has great part in the first favourable effects produced; but the liquid soon acquires the temperature of the body, and is then useful merely as water, by its sedative and diluting qualities.