researchers, including michael welch, chair of the american academy of pediatrics' section on allergy and immunology. a safe temperature for the bathwater is generally held to be 32–38 °c (90–100 °f). japanese bathing culture private baths home bathing (1900s), by kusakabe kimbei today, most homes in japan have a bathroom (ofuro), which was often not the case about 30 years ago. bath water in japan is much hotter than what is usual in central europe. the temperature is usually well above 40 °c. in medical literature, 47 °c is considered bearable. the heat is considered a prerequisite for complete relaxation. the custom is to thoroughly clean oneself with soap and rinse before entering the tub, so as not to contaminate the bath water. until the 19th century, the japanese did not use soap, but rubbed the skin with certain herbs, or rice bran, which was also a natural exfoliant. public baths sento bathing scene. japanese woman bathing in a wooden tub (woodcut by torii kiyomitsu, late 18th century) in public baths, there is a distinction between those with natural hot springs called, onsen (hot), and the other, the sento. since japan is located in a volcanically active region, there are many hot springs, of which about 2000 are swimming pools. most onsen are in the open countryside, but they are also found in cities. in tokyo, for example, there are about 25 onsen baths. locations of known mineral springs spas are on the western model. an onsen, consists mostly of outdoor pools (rotenburo), which are sometimes at different temperatures. extremely hot springs, where even experienced or frequent hot-spring bathers can only stay a few minutes, are called jigoku (hell). many onsen also have saunas, spa treatments and therapy centers. the same rules apply in public baths as in private baths, with bathers required to wash and clean themselves before entering the water. in general, the japanese bathe naked in bathhouses; bathing suits are not permissible. art motif bathing scenes were already in the middle ages a popular subject of painters. most of the subjects were women shown nude, but the interest was probably less to the bathing itself rather than to provide the context for representing the nude figure. from the middle ages, illustrated books of the time contained such bathing scenes. biblical and mythological themes which featured bathing were depicted by numerous painters. especially popular themes included bathsheba in the bath, in which she is observed by king david, and susanna in the sight of lecherous old men. in the high middle ages, public baths were a popular subject of painting, with rather clear depictions of sexual advances, which probably were not based on actual observations. during the renaissance and baroque periods, the gods and nymphs of greek mythology were depicted bathing in allegorical paintings by artists such as titian and françois boucher, both of whom painted the goddess diana bathing. artists continued to paint biblical characters bathing, and also sometimes depicted contemporary women bathing in the river, an example being rembrandt's woman bathing. in the 19th century, the use of the bathing scene reached its high point in classicism, realism and impressionism. oriental themes and harem and turkish baths scenes became popular. these scenes were based on the artists' imagination, because access by men to islamic women was not generally permitted. in the second half of the century, artists increasingly eschewed the pretexts of mythology and exoticism, and painted contemporary western women bathing. edgar degas, for example, painted over 100 paintings with a bathing theme. the subject of bathers remained popular in avant-garde circles at the outset of the 20th century. notable artists who have represented bathing scenes: lawrence alma-tadema pierre bonnard william-adolphe bouguereau françois boucher paul cézanne gustave courbet lucas cranach the younger edgar degas albrecht dürer anthony van dyck roger de la fresnaye paul gauguin jean-léon gérôme albert gleizes jean-auguste-dominique ingres ernst ludwig kirchner boris kustodiev max liebermann édouard manet jean metzinger pablo picasso pierre-auguste renoir sebastiano ricci zinaida serebriakova joaquín sorolla y bastida domenico tintoretto titian anders zorn albrecht dürer, women bathing, 1496 lucas cranach, the golden age, 1530 titian, actaeon surprises diana in her bath, 1559 rembrandt van rijn, diana with actaeon and callisto, 1634/1635 wolfgang heimbach, people bathing, 1640 françois boucher, diana leaving her bath, 1742 torii kiyomitsu, bathing woman, 1750 jean auguste dominique ingres, the turkish bath, 1862 jean-léon gérôme, the bath, ca. 1880 edgar degas, after the bath, ca. 1890 paul gauguin, by the sea, 1892 paul cézanne, the large bathers (detail) lawrence alma-tadema, the baths at caracalla, 1899 max liebermann, bathing boys, 1900 joaquín sorolla y bastida, sad inheritance, 1900. crippled children bathing at the sea in valencia anders zorn, girls from dalarna having a bath, 1906 jean metzinger, baigneuse, deux nus dans un jardin exotique (two nudes in an exotic landscape), 1905–06 albert gleizes, les baigneuses (the bathers), 1912, musée d'art moderne de la ville de paris zinaida serebriakova, banya, 1913 ernst ludwig kirchner, the soldier bath, 1915 pierre-auguste renoir, the bathing women, 1919 boris kustodiev, russian venus, 1926 pablo picasso, quatre baigneuses (four bathers), 1922, collection paul allen in the german spa town bad liebenzell the bather is part of the municipal coat of arms