It seems that my Friday nights have become multiple grocery store trip extravaganzas which means that the refrigerated/frozen products purchased at store # 1 are usually near room temperature by the time I get home from store #4 a few hours later given the time it takes to do other errands along the way. (FYI In case anyone is appaled at the fact that my trip involves 4 stores and several hours, I actually enjoy my lovely 3 hour adventure. I can get all of the specialty products that I want from different stores. It's a nice way to spend a Friday night as I find grocery shopping enjoyable and somewhat relaxing). Obviously, this is not ideal so when at Whole Foods last week I noticed a large insulated thermal reusable bag which I figured would be perfect. It's large and has comfortable straps and holds a lot of food. They assured me that it woudl keep food cool for up to 4 hours. However, when I got home last week 3 hours maximum from my shopping trip, all of the food was barely even cold. Anyone have any experience with these bags? Are there others you'd recommend? I read somewhere on Chow that Whole Foods will accept defective and broken bags, so should I return it if it's not actually keeping the food cold for the estimated time?