Abstract: An apparatus is provided for heating contained liquid, and more particula for thawing frozen blood components which are contained in a bag. The heating apparatus includes a microwave oven which has a cavity for receiving objects to be heated. A track is mounted in the oven cavity and has a peak and a valley with respect to the cavity floor. A tray is provided for supporting the liquid container. A device is provided for pivotally supporting the tray within the cavity with the tray in engagement with the track means, and a device is located within the oven for imparting relative motion between the tray and the track. With this arrangement the liquid container can be moved in a rocking motion to cause a mixing between the warm and cold portions of the liquid, and in particular with regard to frozen blood will cause the thawed liquid portions of the blood to flow over the still frozen portions so as to dissipate heat therebetween.

Abstract: A shielding apparatus is provided for containing frozen bags of fluid and re particularly for containing frozen bags of blood components during microwave thaw. The apparatus includes a metal box for receiving a blood bag, the box having a bottom and sides. A metallic lid is provided, and a hinging device pivotally mounts the lid to the box for enclosing the blood bag therein. The lid and optionally the bottom of the box may be provided with an aperture for allowing microwaves to enter the box. Radiation absorbing strips are mounted along the edges of the apertures for absorbing E field reflections toward the blood bag. The apertures allow microwave energy to be concentrated in the more voluminous part of the blood bag while the edges of bag as well as any tubing are shielded by the metallic box. This apparatus prevents boiling of the blood in the lower volume areas of the bag.