when I pack the lunch bag in the morning, the fruit is cold. I suppose it would be ok to be stored in the lunch bag (which is from Medela breast pump for keeping the milk). But yes, if anything is left, it doesn't look good when we're all back home in the afternoon. After all good suggestions here, for sandwich, I use peanut butter. Now I started to try some bean paste, similar to hummus. Sometime I change the sandwich to cakes (for eggs).