Preparing ice boxes (called Eskys in Australia, or Coolers in The USA) and their contents is critical in retaining ice for lengthy periods. With higher ambient temperatures during summer, correct preparation is especially important during this time.

The first thing you can do is select an ice box with thick insulated walls and lid. A thick insulated lid is important, as a lot of heat can be absorbed into the cooler with the sun beating down on it. Many cheaper ice boxes have lids that are air filled i.e. use air as the insulating material. Good quality eskys in Australia will have high density ISO POLYOL insulation in both the walls and lid.

Next, prepare the esky for your trip. Cool the interior with a little ice slurry (ice and water). Leave the slurry in the ice box for up to six hours. This will cool down the interior and also cool the insulating material. It is amazing how much ice a warm ice box cooler will burn just cooling the box itself down.

Selection of the ice you will use will have the most impact on how long it will last. If you are using party ice, choose crushed party ice for your cooler. This is made from crushing large blocks. This type is solid throughout and well conditioned. Party ice that is manufactured in a machine as individual cubes is not as suitable for your esky as it is often hollow and is considered not well conditioned.

Best of all is well conditioned block ice, either purchased from a supplier, or better still, frozen in your own freezer. Plastic bottles are great for freezing water and best of all; you can drink the cold freshwater from the bottle after it has thawed in the ice cooler. Remember to leave some space for the frozen water to expand in the bottle. You may wish to top up your ice box with party ice to fill the gaps between the blocks, always remember that the more ice the better.

When you fill ice box coolers, it is best to fill it with pre-chilled food and beverage. You will burn a large amount of ice cooling your contents if it is not already chilled. As a guide, it is best to use one third food and beverage to two thirds ice. This two to one ratio will ensure that you have the right amount to keep your contents cool for many days. Many people make the mistake of filling the esky with food and beverage, then adding a small bag of ice with the expectation that it will last for a week. This is not going to happen. As a guide, a good 80 litre cooler will burn 3-5 kg of party ice per day even following the advice in this article.

If you are camping for an extended period of time and ice retention is critical, then fill your esky with goodies and ice the day before. This will cool your contents and the box itself. The next day, empty the ice box of ice, and refill with fresh, well conditioned ice. You are now ready for an extended trip, and your ice will last as long as possible