Hellobee Boards

I don’t know how it might affect the milk, but you should definitely test the bags beforehand. Some plastics can’t take temperatures that low. I’m a scientist, and I’ve encountered a lot of plastic bags that crack at that temperature.

@Hypatia: Not the same, but I used dry ice when we evacuated with my already frozen BM supply for hurricanes. And I added my fresh stuff to it as well, though I had use of an industrial hotel freezer. (Would that be an option?)

What I recall is...
- I broke up the dry ice in chunks so that I was spread throughout the cooler, not just at the bottom, and it was wrapped in butcher paper and then plastic bags.
- I eliminated dead space on the cooler with torn up newspaper and paper bags. The tighter the cooler is packed, the slower things melt.
- Dry ice (in the 5-10 lb size it’s sold) will last 24 hours so you will need to buy more regularly.
- I packed regular ice around the dry ice.
- I double froze what was already frozen, meaning I put the milk bags in another larger ziploc bag (protection) and then put them in an even larger ziploc, added water and froze it. They were rock solid by the time we returned home. Maybe even more effective than dry ice, if the hotel allows you to use the freezer.
- As I said, I kept mine whole cooler in a cold place so I would plan to use the mini fridge. Also I’ve found that mini fridges in hotels can be cold enough to freeze milk. Turn the whole fridge up to the coldest it can go.

Hope it helps!