A method for production of sterile surgical slush outside of a sterile field and subsequent delivery of sterile surgical slush to the sterile field, the method comprising: obtaining the components for the sleeve assembly of claim 14 comprising a sterile container sleeve (200, 1200) and a sterile sleeve cap (300, 1300) which may be engaged with the sterile container sleeve to envelop a sterile sealed slush container (100, 400, 480); obtaining a slush container (100, 400, 480) that contains a quantity of sterile saline, the slush container having a set of interior and exterior surfaces of the slush container starting as sterile; inserting the slush container into an open end of a container sleeve (200, 1200) that covers at least a portion of the slush container; after the slush container is sealed to prevent spilling the quantity of sterile saline, forming the sleeve assembly by engaging a sleeve cap (300, 1300) with the open end of the container sleeve to envelop the slush container, the sleeve assembly is initially sterile but an exterior of the sleeve assembly is deemed not sterile not later than once the sleeve assembly with slush container is placed into a slush making device; placing the quantity of sterile saline which is within the slush container which is within the sleeve assembly into the slush making device located outside of the sterile field; removing the slush container enveloped by the sleeve assembly from the slush making device after conversion of the quantity of sterile saline to sterile surgical slush; separating the sleeve cap from the container sleeve to expose a portion of the slush container; and maintaining the slush container as sterile while removing the slush container from the container sleeve and moving the slush container into the sterile field so that the slush container may be opened and the sterile surgical slush may be used when needed. obtaining the components for the sleeve assembly of claim 14 comprising a sterile container sleeve (200, 1200) and a sterile sleeve cap (300, 1300) which may be engaged with the sterile container sleeve to envelop a sterile sealed slush container (100, 400, 480); obtaining a slush container (100, 400, 480) that contains a quantity of sterile saline, the slush container having a set of interior and exterior surfaces of the slush container starting as sterile; inserting the slush container into an open end of a container sleeve (200, 1200) that covers at least a portion of the slush container; after the slush container is sealed to prevent spilling the quantity of sterile saline, forming the sleeve assembly by engaging a sleeve cap (300, 1300) with the open end of the container sleeve to envelop the slush container, the sleeve assembly is initially sterile but an exterior of the sleeve assembly is deemed not sterile not later than once the sleeve assembly with slush container is placed into a slush making device; placing the quantity of sterile saline which is within the slush container which is within the sleeve assembly into the slush making device located outside of the sterile field; removing the slush container enveloped by the sleeve assembly from the slush making device after conversion of the quantity of sterile saline to sterile surgical slush; separating the sleeve cap from the container sleeve to expose a portion of the slush container; and maintaining the slush container as sterile while removing the slush container from the container sleeve and moving the slush container into the sterile field so that the slush container may be opened and the sterile surgical slush may be used when needed.