After depositing one's clothing in a wicker basket, you take a small towel about 30cm by 100cm and enter a patio like area surrounding the hot water.
Here there are a number of shower areas where you sit on a small stool and shampoo your hair and wash your body using hot water from the tap and then rinse off residual soap with a hand held shower. Any clothing in this area is strictly forbidden. You can put the folded clean wet towel on your head when you enter the water. It must not fall into the water.
A Japanese bath is normally about 41-42'C, but I suspect that the hot spring water is at least 42'C. At 56'C protein begins to denature (cook).
Most people don't stay in the water more than a few minutes.
The hot spring can be located out in the snow as well as indoors and is natural water not the heated swimming pools encountered in Canada's Rocky Mountains.
After leaving the water you dry yourself off and leave feeling much better.
As you can well imagine it is not appropriate to publish or take photographs of the activities.