Brown bag lunches packed by parents can be an inexpensive alternative to school-prepared lunches, but they can also make kids sick if not kept at a safe temperature, according to a new study.

Even lunches that include ice packs can reach unsafe temperatures. In the study, “Temperature of Foods Sent by Parents of Preschool-aged Children,” published in the September 2011 issue of Pediatrics (published online Aug. 8), the brown bag lunches of more than 700 preschoolers at nine Texas child care centers were measured with noncontact temperature guns an hour and a half before the food was served.

Researchers found that 39 percent of the 705 lunches had no ice packs, 45.1 percent had at least one ice pack, and 88.2 percent of lunches were at room temperature. Only 1.6 percent of lunches with perishable items were found to be in a safe temperature zone, while over 90 percent (even with multiple ice packs) were kept at unsafe temperatures.

Study authors suggest that parents and the public need to be educated on safe food packing practices in order to prevent bacteria from growing and potentially causing illness.

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