A sultry twentieth-century Earth song performed in Vic Fontaine's lounge by Lola Chrystal, a holographic singer given Kira Nerys's appearance to help Odo practise courtship in His Way.
Fever is an Earth popular song of the 1950s. It is performed in the sixth-season Deep Space Nine episode His Way, set in 2374, in which the self-aware holographic entertainer Vic Fontaine sets about bringing Odo and Kira together.
To get the stiff constable used to her company, Vic borrows Kira's image from another holosuite programme and builds a nightclub singer called Lola Chrystal around it. She sings Fever with the lounge band while Odo watches, entranced and uncomfortable in equal measure.
Odo finds the imitation unsatisfying because she is not really Kira, so Vic tricks the genuine article into a dinner date. The ruse ends in an argument on the Promenade and the couple's first kiss.