Temporal change of skin temperature after a bathing with warm water is not always the same on all occasions. These differences are remarkably shown between bathing with warm city water and with hot spring water. Exercises have also considerable influence on time course of skin temperature.
It was observed that the hot spring bathing decreased the difference of skin temperature between the left and right side, and the central and peripheral part of the body.

The difference in the thermal change among various organs, such as cutis connective tissue, muscular membrane, muscles, liver, stomach and rectum arose by bathing with city water or many kinds of hot spring water which had been exposed to the air for 20min. Water temperature was 38.5C.
Remarkable changes were seen in the organs of mesodermal origin. This result, I think, shows one of the effects of the hot spring water bathing.
Serum concentrations of several fatty acids greatly increased but that of the rest decreased by taking bath.
Some sorts of hot spring water were considered to promote the fatty acid metabolism. These facts seem to tell that the effects of hot spring water bathing on the connective tissue are some of the main causes of the bathing effect which is peculiar to the quality of hot spring water.