Rod of Asclepius

The Rod of Asclepius is often used to symbolize medicine and EMTs. In the United States, the Rod is confused with Hermes' Caduceus, which has two snakes wrapped around a rod, not one. The Rod of Asclepius is a universal symbol for medicine because it belonged to the Greek God Asclepius, who was the patron of medicine and healing.

Greco-Roman Culture Reference
The Rod of Asclepius is a rod with a snake twirled around it that symbolizes medicine and healing.

One of the main reasons that this is so is because Asclepius, the God of medicine and healing, owned the rod. His rod symbolized his powers, which was to heal and provide care.

The other, allegorical meaning of the Rod of Asclepius is that in medicine, doctors and care-takers must deal with both life and death, two opposite entities. Snakes, in medicine, or both benevolent and malevolent because some fluids in snakes have medicinal properties that were used during the time of the Ancient Greeks, while the snake also had venom, which was fatal. The snake was the embodiment of both life and death, which symbolized medicine.

Though the Rod of Asclepius's symbolism is quite far-fetched, in the United States, whether one sees the Rod or Hermes' Caduceus, he or she will usually immediately associate it with medicine.