How to Protect Your Insulin and Test Strips from the Heat

There are many variables that can affect your diabetes and temperature is one of them. Extreme heat or cold can affect the efficacy of your test strips and insulin if they are not stored properly. During the summer months, this can be tricky with beach days, barbecues and vacation equals heat and sun. But a few simple tips can help you keep your supplies intact.

Insulin should be stored in the refrigerator and is good until the expiration date on the bottle. If any of your insulin has expired, it should be discarded because the insulin will no longer be potent or effective. Once opened, insulin - depending on the type - can generally last about one month at room temperature (59 to 86°F).

Check the package insert to assess how long your specific insulin can last at room temperature. Some insulin pens can only last about 28 days. A vial of insulin is considered open if its seal has been punctured. If you remove the cap but don't puncture the seal, the bottle is still considered unopened.

Blood glucose test strips should be stored in their original container with the lid closed. When you take a strip out, close the cap tightly right away. Humidity and heat can damage the test strip and yield an inaccurate result. Typically, you will find a temperature symbol on your test strip container. Do not freeze them and do not keep them in a room where the air is humid, such as a laundry room or bathroom.

If you are going to be in the heat you should not:

• Leave your meter and insulin in a heated car
• Keep your meter and insulin in direct sunlight
• Freeze your insulin - this can affect potency

Instead, aim to:

• Keep insulin out of direct sunlight: do not leave it in your open beach bag or on your front dashboard.
• If you're going to be outdoors for an extended period of time store your insulin in an insulated case (many of my patients like to use the FRIO wallet, but you any insulated case will do).
• Bring an umbrella to keep your area shaded - your meter operates best at room temperature. Test your sugar under the umbrella and close your test strip case immediately after taking a test strip out.
• If your meter gets too hot, let it cool off before testing your sugar - you can fan it.

If you think that your insulin isn't working properly, check whether it has an unusual appearance.  For example, if it's cloudy when it's supposed to be clear, the color has changed, it's stringy, or it has clumps even after rolling it between your palms, something may be wrong. If you think your insulin has gone bad, don't take any chances: throw the bottle away immediately and open a new one.

It is more common for test strips to malfunction than meters. If you find that are blood sugars are completely out of range, your test strips might get damaged. Check the expiration date and if it's past the date on the bottle, discard them. If you believe your actual meter is not working, you should tell your health care provider and contact the company that made your meter and strips.