Tips on how to keep ice colder for longer with any soft or hard cooler
Pre-Chill Your Cooler and Any Items You're Going to Store in It
One of the best ways to keep your ice colder for longer is by chilling your Treasure Chest before you place the fresh ice in it. You can do so by adding ice a couple of hours prior or even the day before and allowing the cooler to chill as much as possible. This will help prolong the life of the fresh ice once you're ready to go. You can also freeze water bottles or non-carbonated drinks that will act as additional cooling items to help preserve your ice. Also, make sure all of the items you're going to place in the cooler are also well-chilled in advance. Instead of placing hot or room temperature drinks or food into the cooler, freeze or chill as much as possible beforehand.
Use Larger Ice Blocks as well as Cubed Ice
An advantage of using large ice blocks is that they have less surface area exposed to hotter outside air than smaller ice cubes. Thus, larger ice blocks melt at a much slower rate than cubed ice. You can easily make your own DIY ice blocks by using a clean, empty milk carton as a mould. Fill the carton with water (make sure to leave room for it to expand) and freeze. Once frozen, remove the carton and place it in your cooler amongst the cubed ice. The Block ice will keep the cubed ice cooler for a longer period of time.
Organise Your Treasure Chest
As you Zip and unzip the Treasure Chest, warm air will enter, melting the ice quicker. Organise your cooler with items that you will more frequently need to one side to lessen the amount of time the lid remains open. Instead of having to dig around to find what you need, strategically organise your cooler to make each opening as efficient as possible.
Empty Water From the Cooler as It Melts
Despite what you may think, keeping the melted water in the cooler is counterintuitive. Water is much more likely to transfer heat via convection and will encourage the ice to melt further. By removing the water as it accumulates, your ice will melt at a slower rate.
Throw some wet towels over the bag
Using a wet towel or two throw over the bag 1. Keeps the sun off, but it also catches the warm wind and cools the air down which works wonders for keeping ice and contents cold inside your bag.