Hellobee Boards

We have the Zojirushi Ms. Bento but it's probably a bit big for a toddler lunch (I use it to pack breakfast, lunch, and a small snack for LO at daycare because it keeps everything warm).

But I think most of the food thermos containers work if you follow instructions and pre-heat them with boiling water. I just turn our electric kettle on while I get ready in the morning, pour in the boiling water and let it sit for 5-10 minutes, then throw the food I packed the night before into the container. It keeps food warm for 5 hours, no problem.