Sun, warmth, vacation. And diabetes is, of course, packed with you.
Summer brings with it some special considerations that people with diabetes should keep in mind. Temperatures above 30 degrees Celsius, altered daily routines, outdoor activity, and travel influence blood sugar levels more than one might think. Here you'll find the most important tips for a safe and relaxed summer with diabetes, with a wink and without any heatstroke.
1. Insulin and heat: not a good combination
Insulin is temperature-sensitive and loses effectiveness in high heat. Caution should be exercised at 25 °C and above, and it becomes critical at 30 °C. It can quickly become too warm, especially in the car or in direct sunlight. A systematic Cochrane review on the thermal stability of human insulin confirms that above the manufacturer's recommended temperature, insulin activity measurably decreases, at different rates depending on the insulin variant [1]. A critical re-analysis of storage recommendations yields comparable results and emphasizes protection from sun exposure [2].
Tip: Always keep your insulin cool, preferably in a cooler bag or a special insulin cooling case. Ensure that blood glucose meters, sensors, and test strips are also not exposed to direct heat. The exact temperature limits for each insulin variant can be found in the package insert.
At Zuckerschmuck, you'll find every conceivable cooler bag for insulin when traveling, perfectly suited to your needs: from diabetes travel bags to cooling insulin pen cooler bags, cooler bags for insulin vials, or cooling insulin pump bags, we have everything in our range.
Have you already discovered our Frio cooler bags? They are available in many different colors and variations. Here you're sure to find a cooler bag that perfectly suits you. How about this one, for example: FRÍO Design Cooling Travel Bag 2 Pens Tropical.
2. Fluid balance: Drinking is especially important for diabetes
In high temperatures, the body loses fluid more quickly, through sweating and breathing. Fluid deficiency can cause blood sugar levels to rise, as glucose in the blood becomes "more concentrated." At the same time, physical activity or movement can lead to hypoglycemia.
Tip: Drink plenty of fluids. Water or unsweetened beverages are best. 1.5 to 2 liters daily is ideal, more in hot weather. Watch for signs of dehydration: headaches, dizziness, difficulty concentrating, or dry skin.
3. Exercise and sports: good for blood sugar, but not without planning
In summer, many people are more active, whether swimming, hiking, or cycling. This is generally good, but increased activity can lead to hypoglycemia, especially in combination with heat. The DDG practice recommendations on diabetes and sport [3] explicitly recommend: reduce outdoor training in very high heat or high humidity, drink plenty of fluids, and coordinate insulin or carbohydrate adjustments with your diabetes practice to avoid hypoglycemia during and after exercise.
Tip:
- Measure your blood sugar regularly, before, during, and after exercise.
- Always carry fast-acting carbohydrates (e.g., dextrose or fruit juice).
- Also pay attention to the after-effects. Hypoglycemia can occur several hours after exercise [3].
If you're looking for a practical way to store your fast-acting carbohydrates, our hypo boxes are highly recommended: Diabetes HYPO BOX large "Don't eat my Hypo Treats". More tips specifically on the topic of exercise and diabetes can also be found in our detailed main article on sports.
4. Traveling with diabetes: Preparation is everything
Different time zones, altered eating habits, or unaccustomed physical activities can influence blood sugar levels. The risk of forgetting important utensils or exposing them to heat is also higher when traveling.
Tip:
- Take sufficient medication, measuring devices, and accessories with you. Better too much than too little.
- Keep everything in your hand luggage, even on flights. Insulin should not be stored in the cargo hold, as the low temperatures there can impair its effectiveness [4].
- For emergencies: a medical certificate, preferably in English, confirming the carrying of insulin and syringes in hand luggage. diabetesDE provides a printable form for download [4]. Plus a diabetes emergency ID, copies of medical certificates, and if necessary, an international diabetes passport.
To ensure you have all your diabetes-related essentials with you on vacation, we recommend one of our travel bags. The advantage is that you can store everything together and don't have to search for anything. Feel free to browse our Diabetes Travel Bag category. Here you'll find bags in all colors and sizes. You're sure to find one that suits your taste.
5. Do not neglect foot care for diabetes
In summer, people often walk barefoot or in open shoes. This increases the risk of injuries, sunburn, or burns. Especially with diabetic neuropathy (reduced pain sensation, a possible long-term complication of diabetes), small injuries can quickly be overlooked. The National Care Guideline Type 2 Diabetes recommends particularly careful skin observation and daily foot inspection for people with diabetes and sensory or circulatory disorders [5].
Tip (based on the NVL Type 2 Diabetes [5]):
- Wear protective footwear, even on the beach or by the pool.
- Regularly check your feet for injuries or pressure points.
- Take good care of your feet. Dry skin or cracks can be entry points for infections.
- For nail and callus care, do not use sharp instruments, but rather a file and pumice stone. Apply skin care creams to the sole and top of the foot, not between the toes.
- Treat athlete's foot consistently, carefully dry between toes after bathing.
You can find many different products for skin protection and skin care here: Skin Protection and Adhesive Removers.
Conclusion: A safe summer with diabetes, with planning and mindfulness
Getting through the summer with diabetes is absolutely manageable if you keep a few things in mind. Heat, fluid balance, physical activity, and good preparation make all the difference. And even if summer brings its challenges, with the right approach, you can fully enjoy the warm season.
References
- Richter B, Hemmingsen B, Metzendorf MI, et al. Thermal stability and storage of human insulin. Cochrane Database of Systematic Reviews 2023, Issue 11. Art. No.: CD015385. DOI: 10.1002/14651858.CD015385.pub2. Available at: cochranelibrary.com/cdsr/doi/10.1002/14651858.CD015385.pub2.
- Heinemann L, Braune K, Carter A, Zayani A, Krämer LA. Insulin Storage: A Critical Reappraisal. Journal of Diabetes Science and Technology 2021;15(1):147–159. Available at: pmc.ncbi.nlm.nih.gov/articles/PMC7783014.
- Brinkmann C, Halle M, Bracht CG, et al. Diabetes, Sport und Bewegung. Diabetologie und Stoffwechsel 2023. Practice recommendations of the German Diabetes Society. Available at: DDG Practice Recommendations Sport 2023 (PDF).
- diabetesDE — Deutsche Diabetes-Hilfe. Ärztliche Bescheinigung für Flugreisen und Grenzkontrollen. Vordruck zum Download. Available at: diabetesde.org/aerztliche-bescheinigung-fuer-flugreisen-und-grenzkontrollen.
- Bundesärztekammer (BÄK), Kassenärztliche Bundesvereinigung (KBV), Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF). Nationale VersorgungsLeitlinie Typ-2-Diabetes (NVL). Version 3.0, 2023–2025, Kapitel zu Fußkomplikationen. Available at: register.awmf.org/de/leitlinien/detail/nvl-001.
Note: This article is a collection of practical tips and does not replace medical or nutritional advice. For detailed questions about insulin storage (e.g., specific manufacturer's specs for individual insulin variants), consult your pharmacy or the manufacturer. For questions about therapy adjustments related to heat, exercise, or time zone changes, contact your diabetes practice.
