A one-piece mold bottom (7) for a mold (1) for manufacturing containers, includes a molding wall (8) having a raised molding surface (9) bearing the imprint of at least one portion of a container bottom. The mold bottom (7) includes a cavity (27) integrally formed with the mold bottom (7), defined by a surface casing (29) defined entirely by the mold bottom (7) and including an inner surface (31) of the molding wall (8), opposite the molding surface (9) and matching the raised pattern thereof, and a rear surface (32, 33) opposite the inner surface (31). The mold bottom (7) is provided with at least one pair of openings (35; 37) leading into the cavity (27) for circulating a heat-transfer fluid inside the cavity.