What to do about your food if the POWER goes out! Do not open the refrigerator or freezer. Tell your little ones not to open the door. An unopened refrigerator will keep foods safely cold. for about 4 hours. A full freezer will hold the temperature for approximately 48 hours, 24 hours if it is half full. If it looks like the power. outage will be for more than 2-4 hours, pack refrigerated food items such as milk, dairy products, meats, eggs, and left-overs into a. cooler surrounded by ice. Try to obtain block or dry ice to keep your refrigerator as cold as possible. If it looks like the power. outage will last for several days, 50 pound of dry ice should hold an 18-cubic foot full freezer for 2 days. Plan ahead and know where. you can buy block ice or dry ice.