Even insulated sack lunches with ice packs can reach unsafe temperatures quickly

A study just published in the journal Pediatrics brings to light how quickly foods in sack lunches can reach temperatures that risk food-borne illness even when presumably safe measures are taken. The authors obtained data that would apply to sack lunches under other conditions, such as personal food carried for air travel, when they set out to...

"...measure the temperatures of foods in sack lunches of preschool-aged children before consumption at child care centers."

They examined foods packed by parents for 235 children with noncontact temperature guns 1.5 hours before the foods were served to the children. The temperature measurements were made immediately after removing them individually from the sacks (91% of which were insulated). The type of food and number of ice packs in the lunch sack were recorded. What did they find?

"Approximately 39% of the 705 lunches analyzed had no ice packs, 45.1% had 1 ice pack, and 88.2% of lunches were at ambient temperatures. Only 1.6% of perishable items were in the safe temperature zone. Even with multiple ice packs, the majority of lunch items (>90%) were at unsafe temperatures."

Yikes! Even refrigeration wasn't so helpful—only 0.9% of the items stored there (4 out of 458) were an acceptable temperature, although this is probably due to how long the lunches stayed at room temperature before refrigeration and/or the insulated bags kept out the cold. The authors conclude:

"Results of this study provide evidence that how parents pack their preschool-aged child’s lunch has potential effects on the temperature of the food packed and may result in foodborne illness when left uncorrected. Education of parents and the public must focus on proper methods of packing lunches that allow the food to remain in the food safety zone. "

This can account for a lot of unexplained gastrointestinal illness. Moreover, foodborne gastroenteritis can be a trigger for long-lasting autoimmune and allergic disorders. Although this study focused on a pediatric population, the same concerns apply to adult sack lunches and portable meals.