Jewels Doskicz is a registered nurse, freelance writer, patient advocate, health coach, and long-distance cyclist. Jewels is the moderator of Diabetic Connect’s weekly #DCDE Twitter chat, and she and her daughter both live healthfully with type 1 diabetes.

What happens when insulin is exposed to heat?

Ann Williams, Certified Diabetes Educator, likens insulin to a soup broth. Insulin is a protein that's essentially dissolved in water and is capable of spoiling. She goes on to explain that "bacteria growing in it will break down the protein"; this doesn't cause illness, but it does destroy the effectiveness of insulin.

When should I be concerned about my insulin?

If your insulin isn't controlling your blood sugars well, it could be because your storage practices have been subpar.

Insulin should be kept between 36 and 46 degrees Fahrenheit. Insulin can also freeze if it's kept too cold, so heat isn't the only problem.

Insulin can be stored at room temperature once opened for 28 days, the preservatives in insulin keep it usable, unless your room temperature is * higher than 86 degrees*.

Insulin pen cartridges have different recommendations than vials — check the package insert as some can only be at room temperature for two weeks.


Research from the Endocrine Society is eye opening. Of the people that knew the effects of heat on their diabetes medications and supplies, a shocking 37 percent decide to leave them at home rather than bringing them along in a cooler. Additionally:

73 percent of study subjects reported that they received information about the effect of heat on insulin.
• In comparison, only 39 percent reported knowledge about heat and oral diabetes medications.
41 percent were educated about heat and glucose meters.
38 percent stated they knew of the effects of heat on glucose test strips! (This is scary—if strips are faulty and results are incorrect, insulin doses will also be incorrect.)

Portable storage devices

• Coolers are obviously the easiest way to store insulin. Be careful not to place a bottle directly against ice.
• Check out Frio for backpacking or travel when coolers aren't a possibility. With no refrigeration or ice needed, Frio has it dialed with water-activated cooling bags.
ClimaPak is another inventive product that holds a charge for three to five days, has precise temperature control, and is compact and portable. It holds two vials, two insulin pens, or one of each.

Oral diabetes medications

If you're not sure about temperature ranges for your specific medication, look no further than the package insert, or make a quick call to your pharmacy.

Drake University pharmacy professor Geoff Wall told the Sun Times that temperatures can change the chemical composition of many medications. If you live in a warm environment, you may be tempted to store your medications in the refrigerator, but that is a humid environment and isn't for all medications.

Never leave your medication in a car—just imagine what a gallon of milk morphs into. Pills and capsules can crumble and melt and other changes may not be obvious to the naked eye.

Mail order medications

Be sure you know when your insulin and oral diabetes medications will be delivered if you use a mail order company. If it's summer, ensure your insulin is sent overnight and is packed with plenty of ice packs in temperature-retaining packaging. Oral medications are just as vulnerable if they're left in a sunny mailbox all day.

Have any medication disaster stories? Share in the comments below.

For more information about summertime and diabetes:
Don't Let Diabetes Ruin Your Summer Vacation
Avoid These 3 Summer Nutrition Hazards
Summer and Sunglasses: Protect your Eyes