When the Power Goes Off
If you suspect the power may go off, set the freezer control for -10°F to -20°F. The colder the foods, the longer they will keep. Do not open a freezer if the power fails. Opening the doors hastens thawing. Several factors influence the speed of thawing. The food in a fully loaded freezer will last longer than a half filled one. Pile the foods together to keep the foods frozen longer. Group meat and poultry to one side of the freezer or on a tray so that if they start to thaw the meat juices will not get onto other foods.
A freezer with frozen meat will stay frozen longer than one with lots of baked items. A large freezer will keep the foods frozen longer than a small one.
Cover the freezer with blankets to help hold in the cold, but dont cover the vents. If the power might be off for several days, use dry ice to keep the temperature below freezing. Twenty-five pounds of ice should keep a full 10-cubic-foot freezer below freezing for three to four days and a half full freezer for two to three days. Keep foods away from the dry ice and do not handle the dry ice with your bare hands, use gloves. When using dry ice, the room should be ventilated.
Block ice is better than dry to use in the refrigerator. A large block of dry ice could freeze everything in your refrigerator.
In emergency conditions, the following foods should keep at room temperature (above 40°F) a few days. But discard anything that looks moldy or has an unusual odor.