yes, i think so. i've left it out on the counter before for everyone to graze on during the day and it was fine. also, you can get a freezer pack to put in with your lunch to keep it chilled for a few hours. i got some just at my grocery store for less than $2 each. they work great, and then just refreeze them each night.
Starting weight 2/22/12: 275
Goal weight: 140ish