Body temperature naturally fluctuates somewhat throughout the day but stays within a relatively narrow range (usually less than 2℉). Some things that can push your temp upward: sitting in the sun on a sweltering day, battling an infection (in some cases even a mild one, like a cold), and—you guessed it—high blood glucose levels.
This problem occurs in people with Type 1 and Type 2 diabetes, as well as anyone with metabolic dysfunction. It can also happen in relatively healthy people who simply consumetoo many carbohydrates, which causes a spike in both glucose and insulin.
Why Glucose Spikes Can Raise Your Body Temperature
There are two main reasons why elevated glucose levels are connected to body temperature, and they’re closely related.
The first has to do with glucose itself. When glucose gets too high (either chronically or as the result of a big blood sugar spike), your body can react almost as if you have an infection. When you contract an infection, your immune system kicks into gear in an attempt to fight it.
Your body releases prostaglandins (key immune-mediating proteins), which cause body temperature to rise. Prostaglandins then activate other immune system chemicals called histamines that also play a role in regulating body temperature. These same immune system changes occur when your glucose rises too high.
The second key mechanism stems from insulin. When glucose increases, so does insulin.
Recent research has found that insulin may activate genes that control body temperature. Previously, it was already well-known that when insulin is elevated, it stimulates the sympathetic nervous system, which leads to increases in epinephrine (adrenaline) and norepinephrine. These hormones increase heart rate and cause blood vessels to contract and constrict. That makes it harder to cool off because the blood vessels need to dilate and create more surface area to let heat dissipate from deep within the body so it can move to the skin (and eventually to the air around your body).
Epinephrine and norepinephrine also stimulate glucagon, a hormone that prompts your liver to release stored glucose. As a result, blood glucose levels rise, further contributing to the increase in body temperature by triggering the release of more prostaglandins.
Scientists don’t know exactly why all this occurs, but when body temperature rises, metabolic rate (the rate at which we burn energy) also increases. This suggests that your body might be attempting to speed up the rate at which it uses glucose for fuel to lower blood glucose levels.
Why Elevated Body Temperature Is Problematic
Beyond the discomfort of being hot and sweaty, even a body temperature rise of a few degrees can be problematic for your health, especially if it happens chronically over a long time. Enzymes slow down, electrolytes get too low, and hormones don’t work as well. That means cellular reactions might not occur efficiently or adequately, and fluid balance in your body might be disrupted.
In general, people with diabetes struggle with body temperature control, and the same might be true for others with chronically elevated blood glucose. This can be especially problematic when the body can’t cool down as well in hot weather or during exercise.
In these scenarios, the body naturally produces more heat. A comparable increase in heat loss usually balances this out: Blood vessels dilate, you sweat, and the body cools down as the moisture evaporates off your skin. In people with diabetes, however, the “heat loss” side of the equation is compromised. During a bout of exercise, someone with diabetes keeps up to 44% more heat than a comparably sized person without diabetes.
Whether you have diabetes or not, higher body temperature can disrupt sleep. It’s a common cause of waking during the night, and sleep disruption can, in turn, impact glucose metabolism as well as hormones secreted during sleep. This can lead to metabolic dysfunction and diabetes or worsen diabetes if you already have it.
What You Can Do for Stable Glucose and Body Temperature
Specific lifestyle changes can help improve metabolic health (but if you have diabetes or prediabetes, work closely with your doctor to manage glucose levels).
Strategies to lower glucose levels and improve metabolic fitness include:
- Limit sugar and refined carbohydrates
- Get regular exercise
- Prioritize sleep (7-9 hours for most adults)
- Minimize stress
- Eat enough fiber (~50 g per day is a good target)
- Eat fat and protein before consuming carbohydrates
Maintaining stable blood sugar and healthy insulin levels can help keep your body temperature in an optimal range.
Of course, elevated glucose and insulin aren’t the only reasons you might often feel hotter than others in the same room, so if you’re experiencing this issue, consult your doctor. An overactive thyroid (hyperthyroidism), menopause-related hormonal changes, and anxiety are among possible health conditions that might be to blame.
Levels advisor Benjamin Bikman, PhD, is the author of Why We Get Sick. A scientist and associate professor at Brigham Young University, he studies the role of elevated insulin in obesity and diabetes.