Latin term to denote Roman-style winter baths, as opposed to thermae aestivales. Both types of baths are often found close to each other or are sometimes structurally linked. Alternative terms are balneum hiemale or balnearia hiberna. Some uncertainty remains as to the distinctive characteristics of these seasonal baths. It seems that the winter baths were smaller and had fewer and smaller pools than the summer baths. The heated section was also smaller, as heating large rooms in winter meant higher fuel costs. In known North African examples, the winter baths had closed rectangular latrines, as opposed to the large semicircular latrines of the summer baths. See also thermae aestivales.