How Does A Cooler Keep Things Cold?


Taking a holiday picnic or going on vacation offers us the perfect opportunity to spend quality time with friends and family. During these excursions, having a cooler is absolutely indispensable.

A cooler or an ice chest is a portable box, where you can store your food and beverages in a cooler atmosphere so that they won’t heat up and run into waste.

Locally, it is called chilly bin. Using it for a while, have you ever come to the question that, how does a cooler keep things cold?

Well, there's an interesting science behind it. I’m a person from science, I am glad to enlighten you about the function of a cooler.

So, before jumping into the science behind it, let’s have a look on its mechanism.


Well, basically only two things are used to make a cooler. Plastic shells and heat insulating substances.

As it is the structure of box, the outer and inner shells are made of thick plastic. And in between those two shells, heat insulating substance is placed. Styrofoam is an insulator substance, rapidly used inside the cooler. These Styrofoam’s have lots of small gaps filled with air. Consider it as the third element.

Science behind it:

Before starting, let’s have a scientific chit-chat. Heat can travel in three ways. By conduction, radiation and convection. You need to know only two ways to understand a cooler. Conduction and convection.

Conduction means the transfer of the heat from molecule to molecule. It basically occurs on solid substance. And convention means the transfer of heat through liquid or air circulation.

Styrofoam is an insulator. It is a solid substance and hardly transfers heat from the inner and outer walls. So the warm temperature of the exterior is hardly exchanged with the cold temperature of the interior.

Again, I have mentioned it before that insulator like Styrofoam has lots of atomic holes filled with a small bunch of air. However, the amount of air is so light and surrounded with such stiff wall of foams, that they can barely move let alone circulating heat.

The only way of transferring heat from the outer atmosphere when you open the box to take something from it. Otherwise, it is the ultimate heat transfer proof tool.

Types of cooler:

There are many varieties of cooler available in markets. For your single use to family use, you'll find all kinds of them in all sizes out in the shop. Modified version of the cooler has wheels in it so you can slide it instead of pulling it up when necessary.

Rotationally moulded coolers are quite in hype these days. Because a thick layer of plastic is put over both sides of the insulator. So there are barely any gaps between the plastic and the insulator.

It is hard for you if you are a beginner, to get along this entire but do know that, you can actually boost the performance of your best cooler. You don’t need to buy an expensive cooler from the very beginning. You can bring out the best from a cheap cooler too!!


  • Do you know that salt water has a lower freezing point and higher boiling point than water? So to keep your foods cool for hours, instead of regular ice, use saltwater ice.
  • Don’t use small ice cubes. Rather use ice blocks and bottled ice.
  • Consider using an extra layer of insulator to cover everything from the top. In this way burst of warm air will not be able to sneak in at a time when the box is opened.
  • Cool air always travels down. So always put your food at the bottom then the salted ice bars and lastly, things that you need rapidly like cold drinks and beers, just put them on the top. And your arrangements are done.
  • Always keep everything packed in cooler. Even the ice blocks. Otherwise, you will discover your cooler as a muddy pool of rotten foods.


Now that you've come all the way down, let me tell you that cooler is an amazing example of the thermal insulator which is very useful in our daily life. There are specialized coolers for fish and ice cream to carry them on hot vehicles. They are also used for campaigning to keep your food fresh for days.

All thanks to the cooler that you can enjoy outings with good food and a good stomach. Protection Status
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