A container (10) for a beverage has a conventional external configuration with a cylindrical wall (12) closed by a top member (14). The base member (16) closing the other end of the wall (12) is shaped to form an external cavity (20) which extends within the container along its longitudinal axis (A-A). The wall (17) defining the external cavity (20) has a surface in contact with the contents of the container and this surface has a large surface area. The contents of the container can be kept hot, or kept cold by the insertion of an insert (30) into the external cavity (20). To ensure good heat transfer, the insert (30) is push fitted into the external cavity (20). The insert is heated or cooled before it is inserted. The container (10) is configured to be substantially the same size and shape externally as conventional containers, although it does have a smaller capacity. It can therefore be filled on the usual filling lines. Furthermore, the container can be filled and treated before any insert is retained therein. This enables treatments such as pasteurisation to be carried out.