Body temperature is relative to age

THE FACTS Body temperature is not as simple as conventional wisdom suggests. It is influenced by many factors. One of them is age. Body temperature declines with age.

Years ago, scientists discovered that the normal resting body temperature for adults varies from person to person, but that the average temperature is close to 98.2 degrees Fahrenheit, not the widely stated 98.6 degrees. They also confirmed that body temperature rises from morning to evening.

Since then, some studies have shown that normal temperature seems to decline very slightly from decade to decade as well, and that the decline becomes particularly pronounced in older people. It sounds minor, but studies suggest that even a drop of a couple degrees could lead to serious fevers going unnoticed because of deceptively low temperature readings.

One study demonstrating this was published in The Journal of the American Geriatric Society. The scientists examined nursing home residents and found that about half who had infections showed temperatures below 101 degrees, even though many had “robust” changes in temperature — an increase of 2.4 degrees or more — indicating a potentially serious fever.

Lower baseline temperatures is one problem. Another is that a fever is part of the body’s defense mechanism against infections, and this immune response may be diminished in some elderly people, including, studies show, in up to 30 percent of those with serious bacterial or viral infections

THE BOTTOM LINE Some studies suggest normal body temperature can decline with age.