What was a common architectural feature found in Roman baths intended for hot baths?

The calidarium was the section of Roman baths specifically designed for hot baths. It was typically characterized by its warm, steamy atmosphere and was an essential part of the bathing complex, where bathers enjoyed the benefits of heat to relax muscles and cleanse the body.

The calidarium was often equipped with a hot-water pool, and the ambient heat was maintained through various methods, including heating water through a system of hypocaust. The hypocaust involved a network of underfloor heating, which allowed for hot air from the furnace to circulate beneath the raised floors, further enhancing the warmth of the calidarium.

In contrast to the calidarium, the frigidarium, another area in the baths, was designed for cold baths and did not provide the hot, humid environment that was characteristic of the calidarium. The palaestra functioned as an exercise yard and wasn’t specifically related to the bathing experience. The hypocaust, while important for heating, refers to the method used to heat the bath spaces rather than being a specific bathing area itself. Thus, the calidarium stands out as the defining feature associated with hot baths in Roman bathhouses.