Options for Refrigerated Trucks for local driving?

Interesting situation - I'm interested in finding out about any type of refrigerated unit for an area food shelf. There is no 'home' building for this nonprofit and so they don't have a massive refrigerator anywhere but we use the occasional bus storage building for distributions. Needs to be cold enough to store milk/eggs/vegetables/etc. I thought there might be a solution in refrigerated trucking. Is there a refrigerated truck, or even a van, that can be plugged into an outlet when not in use (would need to keep stuff cold for a few days in between trips) but still run on fuel when you are out delivering?

Or is there something other than a refrigerated truck that would still be mobile and fit the bill?

Thoughts?