Suna-mushi onsen, the sand bath in Ibusuki

Suna-mushi onsen (natural sand bath) is a very unique style of onsen in Ibusuki, Kagoshima.
Along the coast of Surigahama in Ibusuki city, there are hotels or onsen facilities which serve suna-mushi onsen style bath.

When you take the bath, you will take the procedure below.
At first, you change your cloth into a yukata (Japanese bathrobe) in a building.
Then you go outside, and walk to the suna-mushi onsen place on beach side.
They set a roof over the onsen place.
You enter under the roof, cover your head with a towel and lie down on the sand bed following instructions of onsen workers there.
Then, the workers put plenty of sand on your body by spade.
You are buried in the sand bath except your face.
Onsen is go through under the sand bed, so you will feel a heat on your back soon.
You begin to sweat all over youｒ body.

When I went to the onsen place and tried the suna-mushi onsen, an onsen worker told me 10 minutes is enough to get the effect of the onsen.
Also he told me some customers didn't follow the instructions of the workers and stayed far more than 10 minutes.
According to the worker, finally the customers got burned by heat of the onsen.

Actually the suna-mushi onsen is very comfortable and good for your health, but it is not good to spend too much time on the hot sand bed.
When you go to there, please follow the instruction by the onsen workers and enjoy safely.