> There is insulation, for sure, but in addition the temperature of what is effectively a large volume ice cube block must rise above 0C before the popsicles ca

> There is insulation, for sure, but in addition the temperature of what is effectively a large volume ice cube block must rise above 0C before the popsicles can begin to change phase (melt). hopefully the "large volume ice cube" is something like a saturated salt or sugar solution so that the ambient temperature it tries to hold is colder than the melting point of the popsicles.