Taking my temperature almost every day has helped me alleviate some COVID-19 anxiety, but only because every time I do it, I end up more worried that I’m the walking dead. To wit: The other morning I had to take my temperature three times just to get a reading above 96 degrees — and I didn’t even have the air conditioning on.
It turns out, taking my temperature right when I wake up, like a kid on Christmas morning waiting for the plague, was my first mistake. “Body temperature varies between people and in the same person, throughout the day,” physician Leann Poston tells me. “Most people have a half degree higher temperature later in the afternoon than they do in the morning.”
Beyond time of day, there are numerous other variables that can cause people to display a temperature lower than the standard 98.6 degrees. One is age: The older we get, the colder we are; whereas babies, children and younger people with a higher metabolic rate (the rate at which they convert calories into energy), all generally have a higher core temperature. Medications like beta blockers and anti-psychotic drugs can lower someone’s body temperature slightly, too, as can alcohol. “Low body temperature is a concern when your body is losing heat faster than it can produce it, such as when in cold environments,” Poston explains.
Ovulation can cause women’s core temperatures to drop slightly as well, but women have a higher core temperature than men overall, despite allegedly always complaining about being cold. (Women tend to experience lower surface temperature on their skin, which isn’t the same as core temperature, even though the two are often confused.)
Another plausible explanation may be that 98.6 degrees is just too damn high. Updated data indicates that the average core temperature has fallen over time, possibly due to humans having a slower metabolic rate due to modernization. To that end, researchers found that at least 75 percent of people have temperatures below the standard, and the average core temperature is closer to 97.5 and 97.9 degrees.
That said, a consistently low temperature can be a symptom of more serious health conditions, like nervous system disorders and hormonal imbalances. Moreover, when the hypothalamus — the part of the brain that controls body temperature — isn’t working properly, it could be a sign of multiple sclerosis, Parkinson’s, a brain tumor and/or a stroke. “[These conditions] can disrupt the regulation of temperature, leading to low body temperature,” explains Vikram Tarugu, a gastroenterologist and the CEO of Detox of South Florida.
When the hypothalamus is working properly, it sends messages to the endocrine system, a group of glands that control the body’s hormones and help to heat up or cool down the body. If the adrenal glands are damaged from conditions like unmanaged diabetes or hypothyroidism, this can also cause people to cool off. “In reality, often a low body temperature serves as an essential hint to a hormonal issue,” Tarugu tells me.
Even certain bacterial infections like sepsis can trigger a lowered temperature in older people instead of an elevated one, so it’s important not to take any chances. Although hypothermia sets in at 95 degrees, Tarugu recommends seeing a doctor if you’re consistently reading below 97.
Speaking of which, when I went for a COVID-19 test and had my temperature taken by a nurse — an even 98 degrees — it was clear my only affliction was an inaccurate thermometer. “If you drink a cold drink or don’t hold the thermometer under your tongue long enough, the oral temperature may be below,” Poston says. “If there’s earwax in the ear canal, ear thermometers may read a false temperature. Forehead or surface thermometers can read low if the angle is wrong.”
Tarugu agrees that more invasive methods are required to obtain an exact measurement of the body’s core temperature. But he says, “In many cases, it doesn’t make sense to opt for invasive methods, despite their reliability and accuracy.” He does note that rectal thermometers can bridge this gap, but “in recent years, rectal measurement of temperature has increasingly gone out of favor because of patient reluctance and concerns that it spreads infections.”
I guess it doesn’t make sense to be so anal about my low temperature after all.