It was reported in the New York Times on March 6, 1927 that so-called “Sunbath tea parties” were the latest fad sweeping London.
Upon arrival at the house hosting the party, guests changed into their bathing suits and then went into a room that was lit by sun-ray lamps. They then would lie down “while enjoying the beneficial rays from the lamps” while they sat around drinking tea, making small talk, and listened to the radio.
Of course, today we know that the UV rays produced by those early sun lamps would later prove to be quite hazardous.