Freezer packs

Carry On Bags: Yes (Special Instructions)
Checked Bags: Yes

Frozen liquid items and gel packs are allowed through the checkpoint as long as they are frozen solid when presented for screening. If frozen liquid items are partially melted, slushy, or have any liquid at the bottom of the container, they must meet 3-1-1 liquids requirements.

 The final decision rests with the TSA officer on whether an item is allowed through the checkpoint.