Lunch pails have come a long way in the past few decades, morphing from plain metal boxes to highly insulated bags with pockets for ice packs. But it still pays to take care when packing a lunch for yourself or your child. You can help prevent food-borne illnesses from packed lunches with these tips from the U.S. Department of Agriculture.

Bacteria thrive at temperatures between 40 and 140 degrees, so it’s important to keep certain foods hot or cold, not in-between.

Pack smart. You have lots of choices when it comes to packing a lunch. If you don’t have an insulated lunch bag on hand, keep food cool by nesting two paper bags. Whatever type of container you use, add a freezer pack or frozen food item to keep things on ice.

Keep hot foods hot. If your child is taking hot soup or chili for lunch, pack it in an insulated bottle. Between uses, wash the bottle and rinse it with boiling water.

Keep everything else cold. You can keep foods cold by using an ice pack or by freezing a juice box or sandwich. Juice boxes and sandwiches taken out of the freezer in the morning should be thawed by lunchtime. Before freezing a sandwich, spread a thin layer of butter or margarine on the bread to keep it from getting soggy, then put it in a plastic freezer bag. Frozen sandwiches can keep for three to four weeks.

The following foods should be kept chilled:
  • Most meat, fish, and poultry, including bologna and hot dogs
  • Cooked vegetables and beans
  • Rice
  • Milk
  • Dressing and gravy
These foods can be kept safely at room temperature until lunchtime:
  • Yogurt and hard cheeses
  • Peanut butter
  • Baked goods
  • Butter or margarine
  • Dry cereal
  • Raw fruits and vegetables
  • Pickles, mustard, and ketchup
  • Dried meats, including beef jerky and pepperoni
  • Canned food
The following foods freeze well:
  • Cheddar and cream cheeses
  • Peanut butter
  • Sliced or ground meat or poultry
  • Fish
  • Cooked egg yolks
These ingredients don’t freeze well:
  • Lettuce
  • Tomatoes
  • Carrots
  • Mayonnaise
  • Cooked egg whites
  • Jelly