A candy striper wearing a nurse's cap
A nurse's cap, sometimes called a Flossie, was a type of hat worn by nurses in the 19th and 20th century, as well as candy stripers.
In 1893, a Devidian disguised as a nurse wore a nurse's cap while visiting the Sisters of Hope Infirmary in San Francisco. (TNG: "Time's Arrow, Part II")
In 1986, candy stripers at Mercy Hospital wore nurse's caps. (Star Trek IV: The Voyage Home)