Hot springs are popular in many parts of the world, but in Japan they are a fundamental part of life. Scientists have championed the positive impact the Japanese bath (onsen) has on health since the early eighteenth century. We already know about the benefits of drinking hot water, and studies have shown that immersing our bodies in hot spring waters can aid recovery from certain conditions including rheumatism, neuralgia, hypertension and skin diseases.

This phenomenon may be attributed to how the hot spring waters help maintain a warm body temperature. As it is more accurately put by the professionals: “There is a physiological mechanism of keeping the body temperature warm by some kinds of hot springs that differs from plain tap water.”

Hot spring waters are heated by geothermal energy. In Japan, hot springs are plentiful. The country is reported to have over 2,500 onsen, with some gushing to the surface while others are reached by tapping sources buried more than 1,000 meters underground. Their temperatures vary widely, from nearly 100ºC (211ºF) to as cool as 20ºC (68ºF).

Types of onsen

There are two types:

• natural spring of geothermally heated underground water
• artificially bored or pumped spring.

Bathers often select their hot springs based on the known healing properties of the water:

• iron-rich springs for soothing painful joints
• sulphur to control blood pressure and prevent hardening of the arteries
• hydrogen carbonate for smooth skin.

The experience

Onsens are often found among mountains, along the seashore or in narrow valleys, which enhance the bathing experience. The open air onsen, offering a backdrop of falling snowflakes, cherry blossom, autumn foliage or summer sunflowers create an experience unlike any other.

The healing properties of water has long since been acknowledged, through the use of hydrotherapy, cold showering and drinking filtered water, to name but a few. For some though, floating in warm therapeutic waters with nothing between you and the sunset, sunrise or dark night skies dotted with countless twinkling stars can be euphoric. It definitely helps in healing both body and mind!

Rules of onsen

Drenched in traditional customs, the Japanese onsen has strict rules of etiquette that must be followed by users:

• Remove your shoes. All onsens have Tatami mat flooring in the changing rooms. Putting outside shoes on these mats is considered to be extremely unhygienic.
• Take care to use the correct changing room – not only would it be embarrassing to enter the wrong changing room, it is also considered a crime!
• Remove all your clothing. The only thing allowed into the bath is a small wash cloth.
• Shower yourself completely before you enter the bath.
• Your wash cloth cannot enter the bath, nor can it lay on the floor at the showers; most people place it on their heads.

The healing properties of the Japanese hot springs are widely acknowledged and enjoyed by many, with as many as 128 million people visiting onsens in 2010.

(Photo by Noriko Puffy)