Heat and Diabetes: Why It’s Crucial to Monitor Blood Sugar in Hot Weather


Controlling blood-sugar levels becomes more crucial in the summer heat, especially for those who have diabetes.

  • Extreme heat can impact blood-sugar control, making it more challenging to keep levels stable.
  • If you use insulin or struggle with effective blood-sugar management, hot weather poses additional risks.
  • Dehydration due to sweating can lead to glucose level spikes, while high temperatures may degrade medications and testing supplies.

To stay safe during summer, closely monitor your blood-sugar levels and be vigilant about hydration and proper management.

How Does Heat Impact Blood-Sugar Levels?

Heat can have various effects on blood-sugar levels, particularly for people with diabetes.

Fluctuating Blood-Sugar Levels

  • It is important always monitor your blood-sugar levels in hot weather.
  • Hot weather can affect blood-sugar control in different ways.
  • Prolonged sun exposure without physical activity can lead to higher blood sugar levels.

Sped-Up Insulin Absorption

  • In warmer-weather conditions, insulin may be absorbed from the injection site more quickly.
  • This is because high temperatures can cause blood vessels to dilate, enhancing insulin absorption.
  • This increases the risk of hypoglycemia.


Medication Damage

  • Insulin stored in hot conditions or exposed to direct sunlight may lose its potency.
  • It is important to store insulin properly, and avoid exposing it to temperatures above 93-95 degrees Fahrenheit.

Increased Risk of Diabetes Complications

Heat Exhaustion

  • Heat exhaustion can occur when the body struggles to cool down in hot weather.
  • People with diabetes may be more susceptible to heat exhaustion due to impaired blood-vessel and nerve function.
  • If left untreated, heat exhaustion can progress to heat stroke, which is a medical emergency.
  • Symptoms of heat exhaustion include:
  • Headaches
  • Dizziness
  • Nausea
  • Muscle cramps
  • Pale skin.

Practical Tips for Managing Blood Sugar in Hot Weather?

Stay Hydrated

  • Drink plenty of water throughout the day, especially when it’s hot.
  • Water is always the best option to keep yourself hydrated in high temperatures
    • Drinks such as non-caffeinated iced herbal teas are effective as well.
  • Drinks that act as diuretics or that have a high caffeine or sodium content can actually dehydrate you.
  • Some examples are:
    • Alcohol
    • Sodas and most energy drinks
    • Coffee
    • Milk
    • Caffeinated tea
  • Sports drinks such as Gatorade can be effective
    • Beware of the high sugar content, and perhaps reserve those carb-heavy drinks for a low blood sugar.

Monitor Regularly

  • Heat can affect insulin absorption, so monitoring helps you adjust your doses as needed.

Store Your Insulin Somewhere Cool

Protect Your Testing Supplies

  • Glucose meters, test strips, and insulin pens can be sensitive to heat.
  • Store them in a cool pouch or insulated bag when you’re out.

Choose Smart Snacks

  • Opt for low-carb, hydrating snacks like cucumber, watermelon, or celery.
  • Avoid sugary treats that can cause rapid blood-sugar fluctuations.

Wear Sunscreen

  • Sunburn can stress your body and impact your blood sugar.
  • Protect your skin with sunscreen and lightweight clothing.

Avoid Overexertion

  • High temperatures can stress your body.
  • Be mindful of physical activity and avoid excessive exertion.

Carry Glucose

  • Always have a source of fast-acting glucose with you (e.g. glucose tablets or gel)
  • In case of a low blood sugar, these can help quickly raise it.

Wear a Medical ID

In case of emergencies, wear a medical ID bracelet or carry a card indicating that you have diabetes.

Do Dry Health & Humidity Affect Blood-Sugar Levels Differently?

  • Both dry heat and high humidity can impact blood-sugar levels— albeit in different ways.
    • Dry heat tends to increase insulin sensitivity, potentially leading to lower blood-sugar levels and an increased risk of hypoglycemia.
    • High humidity can affect hydration levels, influencing how the body processes glucose and insulin.
  • It is important to stay hydrated and closely monitor blood-sugar levels in both humid and dry weather.
  • The Centers for Disease Control and Prevention suggest monitoring the heat index in your area, since that takes both temperature and humidity into account.

Go and Have Some Summer Fun!

As we enjoy the summer sun, remember that—with a few simple precautions—people with diabetes can stay safe and fully embrace the season’s joys.

By staying hydrated, managing blood-sugar levels, and seeking shade during peak hours, you can confidently savor outdoor activities.

Let this knowledge empower you to thrive, ensuring every summer day is filled with health and happiness!

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WRITTEN BY Daniel Trecroci, POSTED 07/05/24, UPDATED 07/05/24

Dan has written about diabetes for more than 20 years. He was one of Diabetes Health's first recruits, and throughout his 10 + years as Managing Editor he wrote/published thousands of articles and helped establish Diabetes Health as the premiere resource for people with diabetes. He later became the Content Manager for OneTouchGold—Johnson & Johnson/LifeScan’s official digital publication for its metering-technology customers. Under his leadership, OneTouchGold received the Web Marketing Association’s award for “Best Health & Wellness" web site. Dan has also written for the Diabetes Research Institute, dLife, diaTribe, Healthline, CareDx, Pendulum Therapeutics, and Hero Bread.