saltwater bath; hot salt bath
A bath with salt added, often for health or relaxation. Can refer to a hot bath at home or at a spa.
On tired days, taking a salt bath warms you up well.
この温泉には塩風呂がある。
This hot spring has a saltwater bath.
温泉 is a natural hot spring, while 塩風呂 is a bath with salt added, which can be at home or a facility.
風呂 is a general bath; 塩風呂 specifically has salt added.
Standard kanji spelling using 塩 (salt).
Alternate spelling using 潮 (tide/brine), also seen.
Compound of 塩 (shio, 'salt') + 風呂 (furo, 'bath'). The alternate kanji 潮 (shio, 'tide/brine') is also used.