Lower Temperature? Chill Out, America : Surprise! Body normal is now thought to be 98.4 degrees for women and 98.1 for men

Over a 16-year period in the last century, a German scientist named Carl Reinhold August Wunderlich took the body temperatures of more than 25,000 people, correlated the statistics and concluded that “normal” was precisely 98.6 degrees on the Fahrenheit scale. For 125 years that number has been medical gospel, virtually unquestioned either by scientists or laypersons. Until now.

In the latest issue of the Journal of the American Medical Assn., a group of Baltimore doctors say that normal body temperature for people they looked at in fact swings over a fairly wide range. Overall, it averages 98.2 degrees, though for women it’s 98.4 and for men 98.1.

Does this mean, then, that the trustworthiness of 100 million household thermometers, their little arrows pointing to 98.6 with a certitude that brooks no dissent, is suddenly cast into doubt? Well, maybe. For some people. At certain times. But, like a stopped clock, which at least is right twice a day, 98.6 can still be a perfectly “normal” temperature for a great many people. Read on.

Dr. Philip A. Mackowiak, who headed the research at the Baltimore Veterans Affairs Medical Center, notes that the new findings are based on 700 oral temperature readings of 148 people between the ages of 18 and 40. Children, the middle-aged, the elderly--a majority of the population, in other words--were not included in the study. The study supported Wunderlich’s findings that body temperature is generally cooler in the morning and warmer in the evening.

What then would define fever in the age group studied? The researchers say an early morning temperature greater than 98.9 or an evening temperature greater than 99.9 can be taken as a sign that perhaps all is not right.

The estimable Wunderlich, who recognized that fever is a symptom of an illness rather than a disease itself, had to make do with thermometers whose calibration was considerably cruder than what’s available today. Moreover, he used the closed armpit to take his readings, a site that generally produces cooler readings. As a result, it now appears, his conclusions about what should be defined as normal temperature were marginally though not alarmingly off the mark.

In any event, Dr. Mackowiak says, the take-home message is that “normal temperature is not a specific temperature but a temperature within a range.” At least for those between the ages of 18 and 40. The new findings, then, are really nothing to get all hot and bothered about.