Keep or toss: Son made his lunch last night (sliced turkey sandwich with mustard & a piece of baked chicken on the side). Put it in his lunch box (metal containers) with a slim ice pack. Let it in his backpack all night instead of the refrigerator. Husband said it was still "cold" this morning. Changed the ice pack and was going to send it to school. Lunch 5 hours from now. Said it smelled fine.