The Rod of Asclepius is a single serpent wound around a plain, unwinged staff, the standing emblem of Asclepius, the Greek god of healing and medicine, whose major sanctuaries, above all Epidaurus, functioned as combined temple and treatment complexes where the sick came to sleep in a designated hall in hope of a healing dream or a direct encounter with the god, a practice called incubation.
Burkert's account of Greek religion treats Asclepius's cult as unusual for the degree to which worship and what would now be read as medical practice were the same activity conducted in the same space, priests functioning as both cult officiants and practitioners of the therapeutic methods, herbal, ritual and dietary, associated with the sanctuary. The serpent itself, kept live in some Asclepian sanctuaries, was understood as an embodiment of the god's healing power rather than as a separate symbol attached to him.
Live, non-venomous snakes, generally identified with the Aesculapian snake found across much of southern Europe, were kept within the temple precincts of major Asclepian sanctuaries as part of the healing environment itself, a detail that grounds the emblem's serpent in an actual sanctuary practice rather than a purely symbolic association invented after the fact.