If I'm going to be pounding the pavement all day, I need protein in the morning. What I do is bring several ziploc freezer bags with me, so I can rig a less-cold way to store some deli ham. I always get a roll of paper towels on the grocery stop, too; if you have food you'll need them.
I buy deli ham (it MUST be a preserved meat, either smoked or sugar-cured; pork seems to work best. Don't try this with chicken or turkey, as it will spoil too quickly), then wrap the deli pkg. in a few layers of paper towels before sealing it in a ziploc. I put it on top of the ice in the cooler, not buried down under it as I would with milk. Stored this way the ham will stay cool, but will not freeze.
In add'n to milk, I also buy the pint bottles of not-from-concentrate orange juice; they are just the right size to get 2 glasses each morning, since we only have 2 people who want it in the morning. Publix has very good muffins that keep quite well; we like those and cereal, as well as the ham. I also keep a bag of nuts handy; more protein.
