Growing up, I fondly remember trading half of my warm tuna sandwich with a friend for something in her lunch. Both my friend and I relished the warm, mayonnaise-laden sandwich on white bread that my mom packed for me many days. Did you read the word warm? And tuna wasn’t the only warmer-than-it-should-be food I ate – yogurt, bologna sandwiches, you get the picture. About the only perishable food I ate at proper temp was the milk handed out during the lunch hour and not packed away in my lunch.

Back in my day (gosh, I sound old), most lunches were packed in brown paper bags or in tin, non-insulated lunch boxes, and without freezer packs. I shudder at the thought of my kids eating this same lunch, a definite breeding ground for bacteria and a breaker of the 2-hour rule of sitting at room temp. I sometimes wonder how I survived or didn’t come down with food poisoning every week. 

Food poisoning, as we all know, is no joke. According to the Centers for Disease Control and Prevention (CDC) each year 48 million illnesses, 128,000 hospitalizations and 3,000 deaths in this country can be traced to foodborne pathogens. Along with the elderly and those with weekend immune systems, children are among the group of individuals that are more susceptible to severe infections caused by foodborne illness. As parents, we do everything we can to keep our children safe and healthy. Add packing a food-safe lunch to that list.

packing a food-safe lunch

Luckily, times have changed since the days of brown bags and tin lunch boxes. If refrigeration is not available at schools, there are a variety of insulated lunch bags and freezer packs to choose from to help keep lunch at safe temps. My son’s lunch sits in his bag about four hours from the time it’s put in his backpack at home to when he sits down for lunch at school. This time-span is two hours past the CDC’s “two hour rule” for cooked/perishable foods and the time when foods enter the so-called “danger zone” between 40° F and 140° F, in which bacteria can grow rapidly.

I wanted to make sure my son’s food really does stay at a proper temp, which is 40 °F or below. So I did a little experiment on packing his lunch, using a standard kitchen thermometer, and found out what works best. See below for my photo and instructional montage.

Picking the Right Bag

lunchbox sample

I found that flat lunch boxes are easier than the tall ones to keep food in place and kept cold.

Step 1

Step 1

I start by putting in a flat freezer pack in the bag, with some of his food items set aside.

Step 2

 

I put the most perishable item (bagel with cream cheese) on top and center of the freezer pack. The non-perishable snacks/drink are set to the side, helping keep the freeze pack in place. I put the less perishable items (peppers and cucumbers) next to the bagel, so it gets some of that cold. I put pretzels at the top to keep things in place.

I put the most perishable item (bagel with cream cheese) on top and center of the freezer pack. The non-perishable snacks/drink are set to the side, helping keep the freeze pack in place. I put the less perishable items (peppers and cucumbers) next to the bagel, so it gets some of that cold. I put pretzels at the top to keep things in place.

 

Step 3

 

Add in more foods, with some slight rearranging with the apples at the bottom instead, but still quite on top of the freezer pack and bagel still in the center. Notice how all these foods help hold the bagel and cream cheese in place.

Add in more foods, with some slight rearranging with the apples at the bottom instead, but still quite on top of the freezer pack and bagel still in the center. Notice how all these foods help hold the bagel and cream cheese in place.

Step 4

Final result! I add in another flat freezer pack directly on top of the bagel. Close it up and put in his bag. Yes, things may get shuffled, but the bagel stays close and in-between those two freezer packs.

I add in another flat freezer pack directly on top of the bagel. Close it up and put in his bag. Yes, things may get shuffled, but the bagel stays close and in-between those two freezer packs.

Final Result

Success! I used my standard kitchen thermometer at the beginning of my experiment and the cream cheese was 37° F. At the 4 hour mark, I tested the cream cheese again and it was 38° F, just one degree warmer and still safely below the “temperature danger zone.”

For additional tips and information, check out these back to school safety reminders from Fight Bac at or explore Fight Bac’s website, which is a partnership for food safety education.

Know someone who might like this article? Share it with them!

Sign up for our newsletter

Tell a friend about this

Share this recipe

Question? We’d love to hear from you!

Other content you may like