Quick Answer: Hot weather and humidity can impact blood sugar levels in people with diabetes by causing dehydration and insulin absorption changes. This may lead to spikes or drops in glucose levels. Staying hydrated, monitoring blood sugar frequently, and protecting insulin from heat are key to staying safe in hot conditions.
Hot weather and diabetes can be a challenging mix. When the temperature rises, it's important to take precautions to control your blood sugar levels. This blog post will discuss how hot weather and humidity can affect diabetes and what you need to do to stay safe. We'll also cover ways to prevent heat exhaustion if you have diabetes. Stay cool!
Related article: Does Insulin Need to Be Refrigerated?
Diabetes and the Heat
It's a topic often discussed during the summer months, but it's important to know the facts no matter the time of year. When the weather gets hot and humid, it's essential to be aware of how diabetes can be affected. High temperatures and humidity (especially during travel) can cause blood sugar levels to rise and fall rapidly. A temperature rise stimulates the absorption of insulin. So you'll need to take precautions like testing your blood sugar levels frequently to make sure your diabetes is under control.
How Does Heat Affect Blood Sugar Levels in People with Diabetes
Hot weather and heat can cause dehydration, which can, in turn, cause blood sugar levels to rise. When you sweat, you lose not only water but also electrolytes such as sodium and potassium. These need to be replaced in order to maintain proper fluid balance in the body. If you're not adequately hydrated, your blood sugar levels will start to rise. This is why it's so important to drink plenty of fluids when the weather is hot, even if you're not thirsty.
Does heat lower blood sugar?
Heat can indeed cause blood vessels to dilate, which can, in turn, create low blood sugar levels, but this effect is usually only temporary. In most cases, the opposite is true: hot weather and diabetes can cause blood sugar levels to rise. Make sure you test your blood sugar levels more often.
Can heat make your blood sugar go up?
Yes, heat can cause your blood glucose levels to rise and make your blood sugar levels fluctuate more.
What to do to Stay Safe in the Heat
The sun can be hot, and it's always better to stay prepared, so here are a few tips to help you stay safe in the heat:
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👕 Wear loose, light-colored clothing and a hat or visor to protect yourself from the sun.
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💧 Drink plenty of fluids, even if you're not thirsty. Avoid alcohol and sugary drinks.
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🏠 Stay in air-conditioned buildings as much as possible.
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🌳 If you must be outside, take breaks in the shade or cool down.
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📉 Monitor your blood sugar levels frequently.
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❄️ Make sure you use an insulin cooler to keep your diabetes injectables such as insulin or GLP-1s, like Ozempic, Mounjaro, Victoza, Byetta, or Trulicity, cold.
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☀️ Use sunscreen to protect yourself from a strong UV index.
Related article: How to Store Insulin Without Refrigeration?
Preventing Heat Exhaustion if You Have Diabetes
Heat exhaustion is a condition that can occur when you are exposed to high temperatures for too long, especially if you are not used to the heat or if you are exercising. Symptoms of heat exhaustion include tiredness, weakness, headache, nausea, vomiting, and dizziness. If not treated promptly, heat exhaustion can lead to heat stroke, which is a medical emergency. If you have diabetes, you are at increased risk for heat exhaustion and should take extra precautions to stay cool and hydrated.
If you have diabetes, it's important to be aware of the symptoms of heat exhaustion. These include:
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💦 Heavy sweating
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😶 Paleness
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💢 Muscle cramps
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😴 Tiredness or weakness
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😵💫 Dizziness or lightheadedness
If you experience any of these symptoms, it's important to:
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🛑 Stop activity and get out of the heat
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💦 Drink cool, non-caffeinated fluids
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🧊 Apply a cold compress or take a cool shower
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🩺 Seek medical help if symptoms worsen or don't improve
Can humidity affect diabetes?
Humidity often comes along with hot weather, and it can have an impact on diabetes as well. High humidity can make it harder for your body to cool down, which can lead to heat exhaustion. Humidity can also cause mold and mildew to grow, triggering allergies and asthma attacks. If you have diabetes and live in a humid climate, be sure to take extra precautions to stay cool and avoid allergens.
Humidity and extreme heat can also damage your glucose monitor, insulin pump, test strips, insulin, and other medical equipment.
Tips for managing diabetes in summer and hot weather
Keep your insulin cool
When having diabetes, one of the most important medications is insulin and injectable drugs like Ozempic, Mounjaro, or Trulicity and other GLP-1 drugs. You must keep them cool during the summer months (room temperature between 68°F and 77°F and in a refrigerator at approximately 36°F to 46°F), as heat can damage these medications. Always use a travel cooler for refrigerated drugs.
Related article: Insulin and Heat: How to Keep Your Supplies Safe in High Temperatures!
Stay hydrated
It's important to drink plenty of fluids when it's hot outside, even if you're not thirsty. What to Drink (and What to Avoid) in the Heat:
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✅ Water - Always the best choice for hydration
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✅ Unsweetened tea - Helps hydrate without added sugar
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✅ Black coffee (in moderation) - Low in sugar and carbs
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❌ Sugary drinks - Can spike blood sugar and dehydrate
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❌ Alcohol - Increases dehydration risk and affects glucose levels
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❌ Caffeinated beverages (in excess) - Can contribute to dehydration
Check your blood sugars
It's important to check your blood sugars more frequently when it's hot outside. This will help you to catch any highs or lows early and prevent them from becoming dangerous. Make sure you adapt your insulin dose to your fluctuating blood glucose levels.
Protect from the sun
Protect your blood sugar monitor, insulin pump, insulin, and other diabetes equipment from heat, humidity, and direct sunlight. Please don't leave them in your car, by the pool, in the sun, or on the beach. This way, your insulin gets spoiled, and your equipment might get damaged.
Don't forget to protect yourself from the sun and wear sunscreen with a high SPF. Wear loose, light clothing and a hat or visor to protect yourself from the sun.
Wear appropriate shoes
Don't forget to wear appropriate shoes when it's hot outside. This means closed-toe shoes that are comfortable and provide good support. Avoid wearing open sandals or flip-flops as they offer little support and can lead to foot problems.
Avoid the heat if possible
If it's possible to avoid the heat, do so. Stay indoors in air-conditioned buildings as much as possible. If you must be outside, take breaks in the shade or cool down with a fan or cold compress.
Related article: What Happens if Insulin Gets Warm? Essential Safety Tips!
📌 Key Takeaways:
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☀️ Heat and humidity can spike or drop blood sugar levels, so regular monitoring is essential.
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💧 Stay hydrated with water and avoid sugary or alcoholic drinks to prevent dehydration.
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❄️ Protect insulin and diabetes supplies from heat using coolers or insulated cases.
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🧴 Avoid prolonged sun exposure-use sunscreen, wear light clothing, and stay in shaded or air-conditioned areas.
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🚨 Know the signs of heat exhaustion and act quickly to cool down and seek medical help if needed.
💬 We'd Love to Hear From You:
Do you have any personal tips or experiences with managing diabetes in hot or humid weather? Share your advice, questions, or stories in the comments below-your insight could help others in the community stay safe and prepared this summer!
📆 Article Update History:
✅ Updated: March 26, 2025
Originally Published: September 28, 2022
