In a medical reference book from the 1940s, The New People's Physician
(1941), I came across these pictures of kids in classrooms and playing sports dressed only in their tighty-whities. They weren't students at a clothing-optional school. They were actually being treated for tuberculosis. In the days before antibiotics, sunlight therapy (or heliotherapy) was a popular cure for that disease.
"At Leysin, in the Alpes Vaudoises, Dr. A. Rollier instituted the treatment of pulmonary tuberculosis and other tuberculous diseases by means of direct sunlight. The patients spend as much time as possible in the open air, exposed to the rays of the sun."
"Early cases of tuberculosis in young and vigorous people benefit considerably from treatment at high altitudes. Exercise and sport of a not too strenuous nature is advocated."
"At Perrysburg, N.Y., tubercular children study in an open-air schoolroom, stripped to the waist."
"Minimum clothing and maximum exposure to the sun contribute to improving the health of these tuberculous children at Perrysburg, New York. Outdoor classes and fresh air improve general health as well."
"Outdoor air and sunlight, even in the New England winter, are part of the treatment for child tuberculosis patients of the Meriden State Tuberculosis Sanitarium, Meriden, Conn."
An LA Times article
(May 28, 2007) gives some background on the popularity of sunlight therapy for TB:
sunlight therapy, or heliotherapy as it was sometimes called (helios is the Greek word for sun), didn't become popular until a Swiss doctor, Auguste Rollier, began championing it in the early 1900s...
Rollier devised a detailed protocol for how, exactly, to sunbathe for health. He was convinced that early-morning sun was best and that sun exposure was most beneficial when the air was cool. When patients, most of whom had tuberculosis, arrived at his solaria, they first had to adjust to the altitude (his clinics were in the mountains) and then to the cool air. Once acclimated, Rollier slowly exposed them to the sun.
The patients were rolled onto sun-drenched, open-air balconies, wearing loincloths and covered from head to toe with white sheets. On the first day of treatment, just their feet peeked out from under the sheets, and only for five minutes. On day two, the sheets were pulled a little higher, and the patients were left in the sun a few minutes more. By day five, only the patients' heads were covered, their bodies left to soak up sun for more than an hour. After a few weeks, the patients were very tan -- and hopefully very healthy. (The therapy worked for many, but not all.)
And according to a fairly recent article in the Journal of Cell Biology
, "Curing TB with Sunlight"
(Mar 27, 2006), sunlight actually is a fairly effective treatment for tuberculosis:
Ultraviolet (UV) light makes vitamin D, and vitamin D turns on innate immunity to tuberculosis (TB), say Steffen Stenger (Universität Erlangen, Germany), Philip Liu, Robert Modlin (University of California, Los Angeles, CA), and colleagues...
The finding may explain why Hermann Brehmer's 19th century trip to the Himalayas cured him of his TB, and why the fresh air at his sanatoria helped cure others. “Our forefathers knew a lot more about this than we give them credit for,” says Modlin. Eventually, however, sanitoria coddled their patients behind glass, which would have blocked the beneficial UV light.