Temperature extremes can be tough on blood sugar levels. How's it been for you? 

Three rules of thumb for anyone using insulin in extreme hot temps: 

1. Stay hydrated

2. Keep an eye on blood sugar levels

3. Protect your insulin from temperature extremes 

We're going over each of these and why they're so important here: 

1.) HYDRATION:
Extreme perspiration due to heat or illness (fever, vomiting, and/or diarrhea) can quickly cause dehydration. 

Dehydration causes elevated blood sugar levels because as blood volume decreases, the glucose concentration within the blood increases.

Elevated blood sugar can also cause dehydration as the kidneys try to flush extra sugar from the blood by excreting it through urine, taking water with it.

This is a cyclical process that can spiral out of control very quickly: Dehydration can cause elevated blood sugar levels, and those elevated blood sugar levels can worsen dehydration and easily lead to DKA (Diabetic Ketoacidosis, a life threatening condition). 

Add sports/physical activity to the mix, which can cause more perspiration and dehydration and you can see how both hydration and maintaining normal blood sugar levels are crucial factors in the heat. 

The Diabetes Solution Book Study Group just covered Chapter 21 Dehydrating Illness and Appendix B: Hospitalization in Dr. Bernstein's Diabetes Solution book.
If you're not a member, we urge you to review these chapters in the book or join us to be a part of the discussions online.

In addition to simple hydration and pushing fluid intake, electrolytes are important! We love LMNT for optimal sodium levels. If you're choosing another electrolyte mix, check ingredients to make sure it won't spike your blood sugar levels. 

Alcohol consumption can also cause increased dehydration and reduced attention to both hydration and blood sugar levels. Consume cautiously. 


2.) KEEP AN EYE ON BLOOD SUGAR LEVELS:

CGMs (Continuous Glucose Monitors) can have sporadic signals in extreme heat, and with dehydration, the CGM numbers can be completely off due to reduced interstitial fluid. 

Contrary to what many modern CGM manufacturers state, you should confirm your CGM reading frequently with finger-stick testing and this is even more important in the heat. Any time that you feel differently than your CGM number, do a finger-stick test with your meter to confirm before dosing insulin. 

But wait, there's one more thing to consider:

Heat also causes your blood vessels to open up (vasodilation), potentially leading to faster insulin absorption and more severe low blood sugar levels. Vasodilation can also cause a drop in blood pressure and faintness. It’s crucial to monitor your blood glucose and confirm your numbers in hot weather!

3.) PROTECT YOUR INSULIN!

Insulin, whether in a pump or carried with you for injections, needs to be protected from the heat to avoid degrading the insulin potency. At the very least, this means keeping insulin out of direct sunlight and never leaving it in a hot car when you're out and about.

Even better would be to keep your insulin in cooled storage when you're away from home. Some cooling options are a standard insulin cooler, Frio pouch (and new Frio Pump Wallet), a Thermos with ice, a temperature-controlled VIVI cap for insulin pens, or USB-powered medication storage canister. 

* If your insulin has been exposed to extreme temperatures, or you notice that it's not as effective, start a new vial or pen that has been properly stored. 

** I personally prefer the simple Frio pouch and have used the same one for nearly 20 years. Word of warning, though: if you use a Frio pouch, do not put the pouch containing insulin in the refrigerator. The gel pouch can freeze quickly and damage the insulin. I've learned this from experience!

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Above all, we're here to help people lead a healthy, active life and stay safe throughout their experience with diabetes. Keeping yourself safe during hot weather is a part of that.

Get outside and enjoy the beach, hiking, camping and sports - just be safe doing it!

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