Q: Late-summer storms have knocked out my power several times lately. Every time, I’m nervous about the food in the refrigerator and freezer. I used to check the cubes in the ice bin. If they had started to melt, I would toss everything. Is there a better rule of thumb for when items are no longer safe?

A: As long as you keep the refrigerator and freezer closed, they are insulated enough to keep food cold for a while. A full chest freezer, kept closed, will stay cold for three to four days, an upright deep freezer for two to three days, and a refrigerator’s freezer for one to two days. A closed refrigerator should keep food cold for four to six hours.

As soon as the power comes back on, check the frozen food: If there are visible ice crystals and the food feels cold, it can be refrozen.

For the refrigerator, keep a thermometer inside and check it as soon as the power comes back to make sure it’s still below 40 degrees. Fresh meat, poultry, lunch meat, hot dogs, eggs, milk, soft cheese and prepared or cooked food should be discarded if they were above 40 degrees for more than two hours. Fruit, juices and vegetables are OK if they smell OK and don’t show any signs of spoiling.