KEEP THE FREEZER DOOR CLOSED. Keep what cold air you have inside. Don’t open the door any more than necessary. You’ll be relieved to know that a full freezer will stay at freezing temperatures about 2 days; a half-full freezer about 1 day. If your freezer is not full, group packages so they form an “igloo” to protect each other. Place them to one side or on a tray so that if they begin thawing, their juices won’t get on other food. And, if you think power will be out for several days, try to find some dry ice. Although dry ice can be used in the refrigerator, block ice is better. You can put it in the refrigerator’s freezer unit along with your refrigerated perishables such as meat, poultry, and dairy items.

EVEN IF FOOD HAS STARTED TO THAW, SOME FOODS CAN BE SAFELY KEPT. The foods in your freezer that partially or completely thaw before power is restored may be safely refrozen if they still contain ice crystals or are 40 °F or below. You will have to evaluate each item separately. Generally, be very careful with meat and poultry products or any food containing milk, cream, sour cream, or soft cheese. When in doubt, throw them out.

In general, refrigerated items should be safe as long as power is out no more than 4 hours. Keep the door closed as much as possible. Discard any perishable foods (such as meat, poultry, fish, eggs, and leftovers) that have been above 40 °F for 2 hours or more, and any food that has an unusual odor, color, or texture, or feels warm to the touch.

KEEP AN APPLIANCE THERMOMETER IN THE REFRIGERATOR AND FREEZER AT ALL TIMES. This will remove the guesswork of just how cold the unit is because it will give you the exact temperature. The key to determining the safety of foods in the refrigerator and freezer is knowing how cold they are. The refrigerator temperature should be 40 °F or below; the freezer, 0 °F or lower.

Source: www.fsis.usda.gov

USDA: Should a large pot of soup sit on the range until it cools, or should it be refrigerated hot?

Hot food can be placed directly in the refrigerator or it can be rapidly chilled in an ice or cold water bath before refrigerating. Cover foods to retain moisture and prevent them from picking up odors from other foods.

A large pot of food like soup or stew should be divided into small portions and put in shallow containers before being refrigerated. A large cut of meat or whole poultry should be divided into smaller pieces and wrapped separately or placed in shallow containers before refrigerating.

Source: www.fsis.usda.gov

USDA: Is it safe to eat leftover food that was left out on the counter to cool at dinnertime, then forgotten until morning? Will additional cooking kill the bacteria that may have grown?

No. Bacteria exist everywhere in nature. They are in the soil, air, water, and the foods we eat. When they have nutrients (food), moisture, and favorable temperatures, they grow rapidly, increasing in numbers to the point where some types of bacteria can cause illness. Bacteria grow most rapidly in the range of temperatures between 40 and 140 °F, some doubling in number in as little as 20 minutes. Some types will produce toxins that are not destroyed by cooking.

Pathogenic bacteria do not generally affect the taste, smell, or appearance of a food. In other words, one cannot tell that a food has been mishandled or is dangerous to eat. For example, food that has been left too long on the counter may be dangerous to eat, but could smell and look fine. If a food has been left in the “Danger Zone” – between 40 and 140 F – for more than 2 hours, discard it, even though it may look and smell good. Never taste a food to see if it is spoiled.
(Sources: Keeping Food Safe During an Emergency; Fighting BAC!® by Chilling Out; Refrigeration and Food Safety.)

Source: www.fsis.usda.gov