In parallel physicians began advising their patients on the benefits of the "sun cure", citing its antiseptic properties. Sunshine was promoted as a treatment for depression, diabetes, constipation, pneumonia, high and low blood pressure, and many other ailments. Home-tanning equipment was introduced in the 1920s in the form of "sunlamps" or "health lamps", UV lamps that emitted a large percentage of UVB, leading to burns. Friedrich Wolff, a German scientist, began using UV light on athletes, and developed beds that emitted 95% UVA and 5% UVB, which reduced the likelihood of burning. The world's first tanning salon opened in 1977 in Berlin, followed by tanning salons in Europe and North America in the late 1970s. In 1978 Wolff's devices began selling in the United States, and the indoor tanning industry was born.