I noticed that on the beach western people tend to cover their butt, genitals. But for some weird reason they leave a lot of other openings exposed. For example the belly button and the arm pits containing lymphatic sweat glands. In female bathing suits the lymphatic sweat glands in the groin area are also frequently exposed. Meanwhile arabs at the beach wear long gowns covering almost the entire body.
What could cause a culture to cover all the body openings (except the eyes), exposing them only if something needs to enter or exit of a body opening? I mean mouth, nostrils, ears, arm pits glands, nipples, belly button, groin pits glands, genitals, butt. In this fictional culture, all these body openings should be covered at all times with a thing non-transparent cloth, even as a ritual only, except when a body opening is directly in use.
Even though it is just a ritual, what could be the cause why such a ritual was established? Maybe to prevent the spread of infectious diseases, similar to face masks?