Arrange the dry ice around food packages, without the dry ice directly touching them. When power is restored, do not stick your head directly into the freezer. There may not be enough oxygen left for you to breathe. Open the freezer door and let outside air mix in before you examine the food. If food has only partially thawed and there are still ice crystals in it, that food may be safely refrozen.
Partial thawing does, however, reduce quality.
For meat or poultry that has completely thawed, but feels cold to the touch, cook, then refreeze, and use it as quickly as possible. Thawed fruits can be used for high quality jams, jellies or preserves. Baked goods may be safely refrozen, even if completely thawed. But some quality may be lost. Do not refreeze commercially frozen dinners or other products.