Originally Posted by
gardener
Science major here. Had you put some salt on the ice in the ice bucket, it would have worked.
Salt depresses the freezing point of water so a ternary mixture of salt, solid water, and liquid water equilibrates at a new freezing point - temperatures of zero F are easily achievable and this will freeze your ice pack.
Thanks. It's sort of complicated but the reason it did not work was because the ice pack was not of the standard non-porous material; it was an unprotected, unconventional porous material used by the medical center that was getting wet in the ice as it melted, but the incision area was to stay completely dry, so the ice pack really needed to be cold and dry, not cold and wet. But definitely will remember the salt tip for other future needs. Thanks.