Baths applied to the whole surface of the body are, as we have already
seen, among the most powerful means of affecting the human system either
in health or disease. Baths of a temperature less than that of the body,
98°, unless of very brief application, uniformly decrease the bodily
temperature. That the diminution of temperature is not merely local,
being confined to the skin and superficial structures, is shown by the
fact that the thermometer indicates a decline of temperature in the
interior of the body as well. The bath diminishes the production of heat
throughout the whole system, besides abstracting large quantities by its
contact with the body, as previously explained. The diminution of
temperature continues for hours after the bath, especially in cases in
which it was excessively high at the time of administration. Hot baths
have, in general, an opposite effect.