塩化物泉

Chloride is the dominant anion — one of the most common spring types in Japan. The salt leaves a film on the skin that slows evaporation, so the body holds its heat long after leaving the bath; the traditional name 熱の湯 ("the hot water") reflects exactly that. You do not get cold quickly afterwards.

What it is like

Colourless to pale yellow-brown. Unmistakably salty to taste. Leaves a faint salt tightness on the skin as you dry.

Indications (適応症)

Cuts, poor peripheral circulation, sensitivity to cold, low mood, dry skin

Contraindications (禁忌症)

Stronger concentrations can sting broken or sensitive skin.

適応症 and 禁忌症 are the claims a certificate is permitted to state under the Hot Spring Act. They are not medical advice, and nothing here is. If you have a heart condition, are pregnant, or are unwell, ask a doctor rather than a guidebook.