Instant cold packs are fantastic items that every avid adventurer or sportsman should have in their first aid kit. I keep them in my backpack when I go bushwalking with the kids just in case someone rolls their ankle or hurts something.
As the name implies, the pack can be used instantly for situations where you simply cannot wait for a normal ice pack to freeze. So how exactly do you use them?
To use an instant cold pack, you need to squeeze and agitate the cold pack. This combines the chemicals inside the pack to create an endothermic process that instantly cools the pack. Apply directly to injuries or sore muscles or wrap in a thin towel if it's too cold.
Using an instant cold pack is so simple and easy. The entire process simply involves some twisting and shaking of the pack to get it cold.
How to Use Instant Cold Packs
Using a cold pack could not be simpler. Here is a quick step-by-step guide on using them properly.
Step 1: Feel for Inner Pouch
Inside the instant packs are granules containing the chemicals and another small sealed bag filled with plain water.
For the cold pack to work as it should, the inner bag, or pouch, needs to be broken to release the water which will then mix with the chemicals and create the reaction.
It is a good idea to locate the inner pouch or bag with your fingers first. You should be able to feel the smaller bag inside the pack.
Step 2: Break the Inner Pouch
Now comes the fun part, breaking the inner pouch. To do this, you can either twist or squeeze the bag until you hear a pop. Don’t worry. This is not the pack breaking, only the inner pouch.
If the inner pouch is being stubborn, you can lay the pack on a flat surface and give it a good hit until you hear the pop. For my brand of instant ice pack pushing it from the front didn't pop the pouch but squeezing it from the sides made it pop extremely easy.
This pop means that the pouch has burst to release the water so it can mix with the chemical granules, causing an endothermic reaction.
Step 3: Shake the Pack
Once the inner pouch has ruptured, the endothermic reaction occurs. This is a chemical reaction that causes as the granules dissolve in the water.
Shaking the pack speeds up the dissolving process and speeds up the endothermic reaction giving you a colder pack. If you don't shake it the pack will still get cold but not as quickly and it likely won't get as cold as it could.
The more you shake and disperse the liquid around the pack, the quicker it gets cold. At this point, the temperature of the pack should drop to around 35℉ (2℃).
Not quite as cold as an ice pack out of the freezer (which would be around 0ºF/-18ºC) but still cold enough to apply to injuries or sore muscles.
Step 4: Apply the Cold Pack to the Injury
Once you can feel that the cold pack is cool enough, simply wrap the pack in a dry towel, paper towel, or cloth and place the pack on the area of injury.
Depending on the temperature of the pack you may be able to apply it directly to your skin.
You can leave the pack in the area for a maximum of 20 minutes before taking it off. Leaving cold packs on the skin for too long can cause tissue damage or poor circulation in that area.
But, to be honest, instant cold packs usually only last about 15-25 minutes before they warm up anyway.,
As you can see, using an instant cold pack is super easy.
How long Does it Take for an Instant Cold Pack to Work?
The whole process of cooling down is instant and rapid, as the name implies. If I had to give you a number, I would say no more than 30 seconds. This is thanks to a chemical reaction.
The more you shake your instant cold pack the faster it will get cold and the colder it'll get. This is because shaking the pack causes the chemicals in the pack to dissolve in the water faster, speeding up the cooling reaction.
How Do Instant Cold Packs Get Cold?
Instant cold packs get cold due to a chemical reaction called an endothermic reaction.
This happens when the urea, calcium ammonium nitrate, or ammonium nitrate dissolves into the water.
This is because more energy is used to pull the ions in the solid chemical apart than is produced when the ions connect and form new bonds with the water molecules.
This energy needs to come from somewhere and is pulled from the heat of the water in the instant ice pack as this is the easiest available source of heat.
As the energy (in the form of heat) is pulled from the water the entire pack gets cold.
The reaction of the chemicals and the water causes the solution to absorb heat from its surroundings and cool down the temperature of the ice pack.
How Long do Instant Cold Packs Last?
The time that the cold packs stay cold depends on a number of different factors, like the brand and the size of the cold pack. The larger the cold pack is the more overall heat capacity the ice pack has so the longer it will take to warm up.
Some brands work better than others. But generally, most last for 5-10 minutes for smaller ones like I had and 10-15 minutes for larger ones.
What chemicals were used inside the cold pack will also affect how long they will stay cold, as well as the materials used on the outside of the pack. Some materials are better insulators than others.
Wrapping your instant ice pack in a paper towel or tea towel will cause it to stay cold for longer as the towel will act as an insulator. But you'll still only get 15-20 minutes from the ice pack if you're applying it to your warm body.
Check out my article for more information about how long instant cold packs last.
What are Cold Packs Used For?
Instant cold packs can be used for multiple reasons. Here are some common ailments:
- Mild to moderate pain
- Pulled muscles
- Insect bites
Instant cold packs should be used in conjunction with RICE (Rest, Ice, Compression, and Elevation). You can also use hot and cold gel packs along with the instant cold pack.
How to Make Instant Cold Packs Last Longer?
Instant cold packs only last for around 10-15 minutes, but there are some things you can do to make them last a little bit longer. By a little, I mean another 5-10 minutes.
Ways to make instant cold packs last longer:
- Fold the cold pack in a half (smaller surface area = slower cooling rate)
- Wrap the pack in a towel, this is great insulation.
- Place the cold pack in a chilled cooler to use it to keep items cold but also to insulate from the outside.
- Shake the cold pack vigorously when first activate to speed up the cooling process so you start with a colder ice pack.
- Only activate the instant cold pack right when you need it.