How Heat and Humidity May Affect Blood Sugar
Hot weather does not directly alter blood glucose levels.
However, sweltering temperatures affect our metabolism and the release of hormones. Heat and humidity influence how much and how fast we move, how much we perspire, blood circulation, the foods we want to eat, and the activities we choose to enjoy.
Any of these factors, or a combination, might contribute to the experience of dehydration and blood sugar fluctuations.
Six Steamy-Weather Influences
We know when it is sizzling outside that we will sweat, and as the air wicks moisture from our skin the body cools. This cooling system works wonderfully as long as our body remains hydrated.
- If our body is low on fluids, the kidneys receive less blood flow and work less effectively. This might cause blood glucose concentrations to rise.
- If someone’s blood sugar is already running high in the heat, not only will they lose water through sweat but they might urinate more frequently too, depleting their body’s fluids even more.
- When the weather is tropical - hot and humid - the sweat on our skin cannot readily evaporate into the already soggy air. Our innate cooling system is less effective and the risk of heat exhaustion increases.
- Having poorly controlled or difficult-to-control blood sugar can inhibit some people’s ability to sweat. Without this effective natural cooling process, they are at higher risk for overheating—even when the humidity is not too high.
- While many diabetics notice higher blood sugar in hot weather, some individuals need less insulin when the weather turns significantly warmer. Although science has not figured out why this occurs, it may be owed to the dilation or widening of small blood vessels in hot temps. As these tiny blood vessels dilate, the body’s delivery system becomes more efficient—extra insulin and glucose can feed the peripheral tissues.
- Having an illness besides diabetes, such as lupus, can also affect the body’s response to heat and its management of insulin and glucose.
High Heat and our Habits
Humans are creatures of habit, but summer temps often alter typical patterns of exercise, eating, and hours in the sun—which may in turn affect blood sugar.
Exercise. If people discontinue or cut back their usual exercise routine because of hot weather, the change may also show up during glucose monitoring since the body is burning less fuel. Moving an exercise routine indoors where it is air conditioned may affect the length of time you exercise and/or how much energy is expended.
Diet. Sometimes people’s eating habits are affected by extreme heat as well. They may eat different foods or eat less, altering their usual blood sugar levels.
Protection. Though most of us are in the habit of protecting our skin from ultraviolet light, occasionally when having summer fun we get a bit too much sun, and sunburn causes tissue inflammation. The physical stress of a sunburn may cause increased insulin resistance and higher blood sugar readings in some individuals.
Supplies. Some habits, such as caring for diabetes supplies, need to change when the heat is on. Extreme temperatures can break down insulin and damage test strips and glucose meters that are not insulated from the heat. High humidity can alter the effectiveness of test strips and medications that are not tightly sealed.