There are a lot of things that can affect diabetes and blood sugar levels, from exercise and diet to stress and sleep deprivation. However, one thing that might surprise you is the impact of weather on diabetes. Temperature changes can, in fact, influence blood sugar levels and might even contribute to false readings. So, how can you ensure you're staying safe regardless of whether you're enjoying the summer heat or a snowy winter day? Here, we'll review everything you need to know about diabetes, weather fluctuations, and how temperature affects blood sugar levels.
Important Information on Temperature, Diabetes Testing Supplies, and Medication
Regardless of where you're going or what time of year, you need to take extra care of your diabetes-related supplies. Never leave your diabetes supplies (testing equipment or medication) in direct sunlight or hot, humid areas, as doing so can result in inaccurate or false readings. The same applies to extremely cold temperatures. Supplies and medications are extremely sensitive to extreme weather and can lose efficacy and accuracy with exposure. The best thing to do is to talk to your doctor about recommendations for insulated coolers and carrying cases to ensure you have everything you need for ongoing diabetes care in extreme heat or cold.
How Hot Weather Affects Blood Sugar Levels
When temperatures start to rise, people with diabetes or prediabetes can have a few adverse reactions. This is especially notable when outside during peak sunlight or when exercising in warm or humid weather. Heat can put stress on the body, which can raise blood sugar. This can increase insulin resistance and liver glucose release. The following are a few other ways higher temperatures may impact blood glucose levels.
Increased Insulin Absorption
High temperatures dilate blood vessels, increasing the amount of insulin absorbed. This can potentially result in hypoglycemia (low blood sugar). If you're in particularly warm climates or are spending a lot of time outside, test your blood sugar more often and be prepared to take diabetes medications accordingly.
Dehydration and High Blood Sugar
One of the most significant risks for people with diabetes during warmer months is dehydration. Dehydration can contribute to an increase in blood sugar levels as glucose in your bloodstream becomes more concentrated. Although this can happen at any time of the year, it's easier to become dehydrated when it's warm outside. Dehydration can also increase the risk of diabetic ketoacidosis for people using insulin.
While you don't have to hide in your house all day during the summer, it's best to avoid the hottest parts of the day (or at least stick to the shade). You should also ensure you're drinking plenty of water and create a plan in case of blood sugar fluctuations. For example, if you're heading to the beach or out for a lake day, bring plenty of diabetes supplies with insulated coolers and glucagon for emergencies.
Changes in Physical Activity
You'll be more prone to sweating and fatigue when working out or engaging in any type of physical activity outdoors. This can further contribute to dehydration and may also reduce the amount of exercise you can do. To ensure you're getting enough activity for optimal blood sugar control, try moving your workouts indoors with air conditioning during the hottest parts of the year.
How Cold Weather Affects Blood Sugar Levels
Cold temperatures can stress the body, leading to a surge in cortisol levels. While this can give you a much-needed energy boost when you're feeling a chill, it can also change how your body produces and reacts to insulin. This is important for type 1 diabetes, type 2 diabetes, or any other type of diabetes, as you will need to adjust medications accordingly. Some specific ways the cold can affect your body include the following:
Reduced Insulin Absorption
When your body reacts to cold weather, blood typically flows closer to the skin, and flow to the extremities is limited to help keep an elevated core temperature. This decrease in circulation can also slow insulin absorption from specific injection sites, thus rendering it less effective. If there are existing vascular problems, the colder temperature can also make it difficult to get accurate readings using finger pricks and test strips.
Increased Insulin Resistance
When exposed to cold, the body releases stress hormones like cortisol and adrenaline to generate heat. These hormones can raise blood sugar levels and reduce insulin sensitivity, making it harder for cells to absorb glucose. This can lead to higher blood sugar levels (hyperglycemia) in some individuals. The constriction of blood vessels can further contribute to a decrease in insulin's effectiveness and an increase in blood sugar. However, some people with diabetes, especially children, may see blood sugar drops in cold weather as their body shivers and there’s an increase in involuntary movement to keep warm.
Risk of Raynaud's Syndrome
Raynaud's syndrome is an autoimmune condition that can cause the small arteries in fingers (and sometimes toes) to spasm, reducing blood flow to the end arterioles. Low temperatures typically trigger this, but stress can also exacerbate it. If you experience this, you may find that your blood sugar readings are abnormally low when it's cold outside. However, this may not indicate your entire body's blood glucose levels, as only the extremities (fingers/toes) are affected. Therefore, it's important to warm up before you test or use a continuous glucose monitor to avoid issues caused by poor circulation. You should also be mindful of keeping skin well covered, especially if it’s windy outside.
Seasonal Changes in Diet and Activity
Cold weather typically corresponds to holiday parties, family dinners, and less strict diabetes management protocols. While it's absolutely okay to enjoy yourself during these periods, you'll need to test your blood sugar and act accordingly. Dinner with a higher carbohydrate count or a dessert that raises your blood sugar every now and then is a normal part of life and is unlikely to cause long-term issues as long as you're prepared.
9 Tips for Managing Diabetes in Extreme Temperatures
Several studies show a sharp increase in hospitalizations among people living with diabetes during periods of extreme temperatures. Specifically, people tend to experience higher rates of hypoglycemia and sudden cardiac arrest during high (over 100°F) and low (under 10°F) temperatures than when compared to more moderate temperatures. Diabetic ketoacidosis is also more prevalent in colder weather but not in warmer weather. To help manage your diabetes in extreme temperatures, here are a few tips:
Stay Hydrated
Drinking plenty of water is essential for stabilizing blood sugar levels, especially in hot weather when dehydration can increase glucose concentrations. Carry a water bottle with you at all times and monitor your hydration by checking the color of your urine—clear or pale yellow is ideal.
Avoid Excessive Sun Exposure
Spending too much time in direct sunlight can lead to overheating and dehydration, both of which can affect blood sugar. To keep cool, try to stay in the shade during peak sunlight hours, wear protective clothing, and use an umbrella or hat.
Check Your Blood Sugar Levels
Extreme temperatures can make blood sugar levels fluctuate unpredictably, so it's important to test more frequently. Keep extra test strips on hand, and if you use a continuous glucose monitor (CGM), ensure it’s functioning correctly in both hot and cold weather.
Know the Signs of Heat Exhaustion
High temperatures can cause heat exhaustion, which can lead to dizziness, confusion, and extreme thirst—symptoms that can also mimic hypoglycemia. If you feel weak or lightheaded, move to a cooler place, drink water, and check your blood sugar levels immediately.
Stay Active
Regular physical activity helps regulate blood sugar levels, but extreme weather can make it harder to exercise. In hot weather, opt for indoor, air-conditioned workouts, and in cold weather, bundle up and find safe ways to stay active, such as walking at an indoor mall or using home workout equipment. And always pay attention to your body. Walking up a grassy hill might have a small effect on blood sugar, but walking up that same hill covered in six inches of snow may take twice as long and burn three to four times as much glucose!
You should also keep in mind that you may find more pronounced changes in blood sugar when you resume activity in the spring, especially if you took some time off your routine during the winter.
Check Your Feet
People with diabetes are more prone to circulation issues and nerve damage, which can make their feet vulnerable to injuries in extreme weather. Inspect your feet daily for cuts, blisters, or signs of infection, and wear moisture-wicking socks in the heat or insulated footwear in the cold.
Store Medications Properly
Insulin and other diabetes medications can lose effectiveness when exposed to extreme temperatures. Keep them in temperature-controlled environments, use an insulated case for travel, and avoid leaving them in hot cars or freezing conditions.
CGMs may also not be accurate when they’re cold, especially if it’s worn in an area exposed to the elements. Try to wear them on places that will be kept warmer (i.e., the abdomen) and always cover them with warm clothing.
Dress Appropriately
Wearing weather-appropriate clothing can help regulate body temperature and prevent extreme temperature-related complications. Choose breathable, lightweight fabrics in the heat and layer up in the cold to maintain stable blood circulation.
Take Extra Precautions Against COVID-19 and the Flu
Cold weather increases the spread of respiratory illnesses, which can cause blood sugar fluctuations and other complications for people with diabetes. To reduce your risk of infection, stay up to date on vaccinations, practice good hygiene, and avoid close contact with sick individuals.
For additional diabetes support and management, Byram Healthcare offers diabetes care and educational materials available to help you access everything you need for comprehensive care.
