What is the term for the sweating room in a Roman bathing facility?

The term for the sweating room in a Roman bathing facility is indeed Laconicum. This specialized room functioned as a dry heat area, resembling a modern sauna, where bathers would experience a high-temperature environment designed to promote sweating and relax the body. Typically, the Laconicum would have been constructed with benches and would be heated by a hypocaust system, allowing for the circulation of warm air beneath the floors and through the walls, enhancing the effects of the heat.

The other terms listed refer to different components of Roman baths: Natatio refers to the swimming pool area where bathers would enjoy cooler water; Piscina indicates a tank or reservoir, often for fish, which could be found in the baths; and Nymphaeum is a decorative structure dedicated to nymphs, which sometimes housed water features or baths but is not specifically related to the sweating process. Each term represents essential elements of the complex bathing culture of ancient Rome, but the Laconicum specifically stands out as the room intended for intense heat and sweating.