Summer vacation is approaching. It is recommended to keep insulin cool, preferably in the refrigerator between 36°F and 46°F. It becomes a bit harder when you are traveling. I traveled myself in harsh temperatures and I will guide you on how to keep your insulin cold.

In this Diabetic & Me article you will learn about:

  • Do I need to keep insulin cool?
  • How to store insulin while traveling?
  • Can insulin go bad if not refrigerated?

Does insulin need to be kept cool?

Yes, keeping insulin cool is very important. But it depends on the environmental temperature. Unused bottles and insulin pens need to be kept in the refrigerator between 36°F and 46°F. Keep an eye on the expiration date. insulin pens and vials that you are currently using can be stored at room temperature between 56°F and 80°F.

If you are traveling in cold temperatures make sure to keep your insulin warmer than prescribed. It should not freeze or it will be damaged. When traveling in warmer temperatures keep your insulin cooler. You might want to use an insulin cooler or travel case. I traveled in very hot temperatures in Australia and Sri Lanka. I used the Frio cooling bags to store my vials safe and cool while flying on an airplane. When I traveled in the Australian outback I used the 4ALLFAMILY Insulin Cooler.

How do you store insulin when traveling?

There are different possibilities to store your insulin when traveling. It all depends on how you travel.

Traveling by airplane

When traveling by air, keep your insulin in the hand luggage because the temperature in the cargo hold compartment can drop below zero. During the flight, it is better to keep insulin in the refrigerator or in a cooling bag. Most of the time the airplane has a good room temperature and you don't need constant cooling. Try to contact the airline prior to departure whether this is possible. It is also wise to have a completed doctor's statement with you at all times for customs and airport security in addition to a medicine passport.

Always make sure your checked luggage does not contain any medication that can freeze during a flight. You should keep those in your hand luggage at all times.

Traveling by car

In any case, your medication should be kept in the coolest possible place, so not on the parcel shelf or in the glove compartment during a car holiday. Direct protection is also necessary. A great way to protect your insulin during a car holiday is to use a protective travel case. You can also use specialized vial protectors to absorb any shocks and bumps in the road.

The best next thing that comes to mind is to use bubble wrap to wrap your medication. But store it in a cool place it's covered against the heath. A wet cloth also helps if you don't have other options available.

How do you keep insulin cold when traveling?

Being a diabetic doesn't make travel easier. Keeping insulin cool is not always an easy task. There are various ways of keeping your insulin and diabetes supplies cold and protected while traveling. It all depends on the length of travel and the conditions you are traveling in. Thanks to the invention of an insulin cooler and ice packs, it becomes easier to keep insulin cool during your trip. Below I listed a few of the options to keep your medication cool and protected.

USB insulin cooler

A great way to cool your medication while traveling is by using a USB powered cooler. These coolers give you the guarantee to keep your medication at fridge temperature all the time. When the cooler battery is about to run empty you always have the opportunity to charge the cooler via your car, battery pack, or power outlet.

Insulin cooling wallets

A cooling wallet or bag has great insulation to keep all your supplies and medication safe and cool. One of the better-known brands is Frio. They provide you with excellent quality and make sure everything is protected against the heat. The wallet or bag is easily activated when soaking in cold water for a while. After the cooling elements are activated your medication is cooled for over 72 hours.

Insulin travel case

A travel case gives you a bit more room to store medication and supplies. They come with multiple compartments and ice packs. You can also use it at home.

Insulin (single) pen cooler

Most diabetics find the pen cooler an easier solution to use on a day trip due to its compact size. When you are traveling by plane it's easier to go for a bigger solution like the travel cases.

Portable mini fridge

The portable mini-fridges are great for diabetics that are traveling in the car. It's easy to use and you can also store your different kinds of foods.

Illustration Of How Should You Keep Your Insulin Cold While Traveling

How long can insulin be left unrefrigerated?

As a diabetic, it's recommended to keep your insulin always refrigerated.

Unopened insulin can be kept for six weeks outside the refrigerator at a temperature of up to 95°F. Do not put the insulin in bright sunlight! Never use insulin that was exposed too long to bright and direct sunlight.

Once your vials are open and used they may be left unrefrigerated at a temperature between 59°F and 86°F for up to 28 days and continue to work.

Can insulin go bad if not refrigerated?

Yes, it surely can but if preserved correctly it can survive. Never use insulin that went bad and make sure you replace it on time.

Insulin cannot withstand too high or too low a temperature. It then quickly loses its effectiveness. Too high temperatures can easily develop if your medication is exposed to full sun or a tropical warm environment. You should also avoid freezing temperatures.

If you want to check if your medication is still working you can check the time it takes to become active and also check the quality of it. Some insulins are naturally clear, others are milky-cloudy because they are mixtures of two types, or because they are mixed with an agent that extends the duration of action. If your insulin looks different than usual (brownish, or has flakes, granules, or particles in it) it may have been too hot, too cold, or too old. You throw those vials or pens away.

Short-acting insulin lowers the amount of blood sugar after only 10 to 30 minutes; the effect lasts 2 to 8 hours. The medium varieties work after 1 to 2 hours and the effect lasts for 16-24 hours. Long-acting insulin has a continuous effect throughout the day when used as directed.

Do I need a doctor's note to fly with insulin?

It's not a mandatory item. But it makes life easier. When storing your medication in your hand luggage you might get questions from the airport security why you are traveling with insulin vials or insulin pens and needles. Instead of explaining you can show the note from your doctor.

When I traveled to Australia I had to transit to Thailand. Airport security checked my bags and requested an explanation why I was traveling with that many vials, needles, insulin pens, and insulin pump material. I showed my doctor's note, gave them some info about my condition, type 1 diabetes, and that I need these medications to survive. They understood and let me continue on my travels. When I embarked on the plane I talked to the cabin crew, and they put my insulin in a cooler box with ice packs.


Insulin is sensitive and must be kept cool. Therefore, use a protective insulin cooling case that is able to keep insulin on temperature. It doesn't matter if you have type one or type 2 diabetes. It makes life easier.

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About the Author

Ely Fornoville

Hi, I'm Ely Fornoville, and I am the founder of Diabetic Me. Being a type 1 diabetic since 1996, I developed a passion to help people learn more about diabetes. I write about diabetes and share stories from other diabetics around the world. I currently use a Medtronic Guardian 4 CGM and a MiniMed 780G insulin pump with Humalog insulin.

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