Abstract: An improved refrigerated beverage carrier is provided to fit into a bicycle water bottle cage. The beverage carrier is comprised of a hollow, low density plastic flask having a mouth for dispensation of a beverage at one end and a central axial opening at the opposite end. A sealed, hollow, low density plastic core is inserted into the central axial opening of the flask. The core has a blind end located within the flask and an access end adapted to receive refrigerant at the central axial opening. The core is filled with a refrigerant, such as a mixture of propylene glycol and water, and is sealed to the flask by ultrasonic welding. Ultrasound is applied to an end plate having a pair of concentric annular sealing rings. The innermost annular sealing ring, when welded, forms a fluid tight seal with the core, while the outermost sealing ring, when welded, forms a fluid tight seal with the flask.