Kiwi's call them Chilly Bins while the Aussies call them Eskies but what are they referring to?

A cooler, portable ice chest, ice box, cool box, chilly bin (in New Zealand), or esky (Australia) is an insulated box used to keep food or drink cool.

Ice cubes are most commonly placed in it to help the contents inside stay cool. Ice packs are sometimes used, as they either contain the melting water inside, or have a gel sealed inside that stays cold longer than plain ice (absorbing heat as it changes phase).

Coolers are often taken on picnics, and on vacation or holiday. Where summers are hot, they may also be used just for getting cold groceries home from the store, such as keeping ice cream from melting in a hot automobile. Even without adding ice, this can be helpful, particularly if the trip home will be lengthy. Some coolers have built-in cupholders in the lid.