Insulated Frozen Breast Milk Shipper Box with Prepaid Return Mailing Label

• One Insulated Frozen Milk Shipper Box
• Stickers or Tape to Seal the Box
• Plastic Zip Lock Bags
• Filler Paper
• Milk Storage Bags
• Instructions
• Prepaid return mailing label (Includes the continental U.S., contact us for pricing if a label for Alaska or Hawaii is needed)

How to Reach the Full 96-Hour Mark

Under standard ambient travel condition (68°F to 77°F/20°C to 25°C), a properly packed shipper will keep breast milk frozen for 72 to 96 hours (3 to 4 full days) without dry ice.

1. Start 100% Frozen Solid: The milk must be fully frozen in a sub-zero deep freezer before packing. The cooler preserves existing thermal mass; it cannot freeze soft or partially thawed milk.
2. Eliminate All Dead Air Space: Air pockets cause milk to thaw rapidly. The cooler must be filled completely to the top. If you aren't packing enough milk to fill the payload space, fill every remaining gap with frozen water bags or tightly crumpled paper so it forms a single, solid "block of ice."
3. Keep the Lid Sealed: Do not open the box during travel to "check" the milk. Opening the box breaks the internal thermal seal and lets warm ambient air inside.

External Factors That Reduce Thermal Hold Time

• Extreme Heat: If the box is left in a hot car trunk, on a sunny porch, or on an airport tarmac in 90°F+ heat, maximum frozen duration drops to around 48 to 60 hours.
• Partial Loads: A box that is only half full of frozen milk (without filler ice packs) will warm twice as fast as a completely full box.