Extreme heat with diabetes can be dangerous. High heat affects blood glucose levels. Recently, extreme heat has been reported in the United States and Europe. Heat and moderate to high activity can make you sweat profusely, and people with diabetes may become dehydrated, leading to a rise in glucose levels. People with both type 1 and type 2 diabetes feel the heat more than people who don’t have diabetes. Here are the reasons why:
- Certain diabetes complications, such as damage to blood vessels and nerves, can affect your sweat glands so your body can’t cool as effectively. That can lead to heat exhaustion and heat stroke, which are medical emergencies.
- People with diabetes get dehydrated (lose too much water from their bodies) more quickly in high heat. Not drinking enough liquids can raise blood glucose, and high blood glucose can make you urinate more, causing dehydration.
- High temperatures and heat can change how your body uses insulin. You may need to test your blood glucose more often and adjust your insulin dose and what you eat and drink.
Even when it doesn’t seem very hot outside, the combination of heat and humidity (moisture in the air) can be dangerous. When sweat evaporates (dries) on your skin, it removes heat and cools you. It’s harder to stay cool in high humidity because sweat can’t evaporate as well.
High temperatures and heat can change how your body uses insulin. You may need to test your blood glucose more often and adjust your insulin dose and what you eat and drink.
It’s always a good idea to check the heat index when temperatures soar—a measurement that combines temperature and humidity. Take steps to stay cool when it reaches 26°C (80°F) in the shade with 40% humidity or above. Usually the heat index can be up to 15°F higher in full sunlight, so stick to the shade when the weather warms up. For example, if the temperature is 32°C (90°F), a high humidity index may make it feel like 40°C (105°F).
Tips for high heat:
- Drink plenty of water—even if you’re not thirsty—so you don’t get dehydrated.
- Avoid alcohol and drinks with caffeine, like coffee and energy or sports drinks. They can lead to water loss and spike your blood glucose levels.
- Check your blood glucose before, during, and after you’re active. You may need to change how much insulin you use. Ask your doctor if you would like help in adjusting your dosage.
- Wear loose-fitting, lightweight, light-colored clothing.
- Wear sunscreen and a hat when you’re outside. Sunburn can raise your blood sugar levels.
- Don’t go barefoot. Protect your feet always!
- Use an air conditioner or go to an air-conditioned building to stay cool. In very high heat, a room fan won’t cool you enough.
- Physical activity is usually associated with reduced need for insulin. The latter may increase the risk for low blood glucose. in higher temperatures, people are at risk for both low and high blood glucose.
The key in high heat weather is to be vigilant and check your blood glucose often, and seek emergency treatment if necessary.
