Disposable sleeves for containers, and systems and methods using disposable sleeves

A disposable sleeve for a container, the disposable sleeve comprising:

• a liner having inner and outer surfaces and configured such that the inner surface of the liner is adapted to contact the container;
• a housing coupled to the inner surface of the liner, the housing comprising a first surface, a second surface, a pocket defined between the first and second surfaces of the housing, and a continuous opening in the second surface of the housing so as to provide air access to the pocket and to expose a majority of the pocket at the second surface of the housing;
• a heating element disposed within the pocket and covered by the first surface of the housing, the heating element being formed from a piece of heat-generating material that is larger than the continuous opening and smaller than the pocket so that the pocket defines a void between the first and second surfaces of the housing and the void at least partially surrounds the heating element within the pocket, the continuous opening providing air access to the void within the pocket;
• a housing liner disposed within the pocket between the heating element and the continuous opening so that the heating element is completely covered by the housing liner within the continuous opening, the housing liner being porous so as to enable air to pass therethrough to the heating element;
• and
• a cover disposed over the continuous opening and coupled to the housing to contact, cover, and seal the housing liner and enclose the heating element in the pocket within an air-tight encapsulation formed by the cover and the first and second surfaces of the housing, wherein the cover is at least partially removable from the housing to uncover at least a portion of the continuous opening and to enable air to pass through the housing liner to the heating element and thereby enable activation of the heating element to generate heat upon exposure to air.