For those of us who don't have generators to keep our food cold, sometimes a smell test is all we have to go by but experts say that's not enough.

People waited in line for hours at Ice Cream World in Allentown to buy dry ice for their refrigerators.

“We just bought some steaks. We tried a new service, and of course our freezer now is off, so we've never even tried them yet, so we're hoping we'll be able to get those cold enough to keep for a while” said Herb Campbell.

Normally, the cold commodity goes for a $1.55 a pound, but with demand soaring, prices, have almost doubled at $3.00.

“It was brought, I believe, as far as Mississippi. There's just extra costs in getting it here right now. There's extremely high demand, and they're going really far to get it to us, and we're just happy to be able to provide it at all” said owner Kim MacIver.

To keep food cold is key, according to the U.S. Food and Drug Administration. Most refrigerated foods are safe up to four hours after you lose your power.

After that, if your fridge has gone up above 40 degrees for more than two hours, it's time to throw things out, especially if it's dairy, meat, poultry, fish, eggs or any leftovers.

Anything that still has ice crystals or has stayed at 40 degrees or below is safe to re-freeze or to cook.

So what can you keep?

According to FoodSaftey.gov with the U.S. Department of Health and Human Services, most cheeses, especially hard, processed or if it's in a jar or can, is safe. Butter and margarine, fruit juices and canned fruits that have been opened are also safe.

Condiments such as jelly, relish, mustard, ketchup or barbecue sauce are safe, plus opened vinegar-based dressings as well as olives and pickles.

Products such as muffins, tortillas, cakes and bread rolls are also safe.

Breakfast foods like pancakes, waffles and bagels are all OK to eat, as well as raw fruits and vegetables and fresh mushrooms.