With Hurricane Sandy predicted to hit Monday, losing power is a threat. 

The USDA's Food Safety and Inspection Service prepared a fact sheet for keeping food safe during an emergency, including losing power.

The USDA says to "keep the refrigerator and freezer doors closed as much as possible to maintain the cold temperature."

But, the refrigerator will only keep food safely cold for about four hours if unopened during a power outage, according to the USDA. A full freezer will hold the temperature for about 48 hours if full (24 hours of half full), the USDA says.

The USDA emphasizes "never to taste food to determine its safety" and says that you should "evaluate each item separately." 

Generally, if the temperature in the thermometer in the freezer reads 40 degrees Fahrenheit or below, the food is safe and can be refrozen, according to the USDA. The USDA suggests obtaining dry or block ice to help keep refrigerated or frozen food cold if the power will be out for an extended period.

For more details and for a list of "when to save and when to throw it out" for refrigerated and frozen food items, click on this link:

http://www.fsis.usda.gov/factsheets/keeping_food_safe_during_an_emergency/index.asp