Why not invest in one of those small plastic containers with a freezer pack in the lid? I have a lunch box like that made by Fit N Fresh. I believe they make smaller ones and I've seen them at TJ Maxx and Ross lately, so you can pick them up cheap.
If you pack it up the night before, all you need to do is put in the freezer pack and throw it in your bag. The beauty of using a container like that, is that hard boiled eggs and such won't get squashed.


