Behind every famous number lies a story. And in this season of sickness, when the thermometer frequently emerges from the bathroom cabinet, few numbers in medicine are as familiar as 98.6 - the normal temperature of the human body.
Celebrated in song and enshrined for more than a century in schoolbooks and medical texts, 98.6 degrees Fahrenheit is the benchmark many of us use to determine who goes to school or work and who stays in bed.
There's just one little problem: 98.6, it turns out, is a medical myth.
While it continues to circulate in publications ranging from this month's Parenting to the Bantam Medical Dictionary, studies in recent years have shown that 98.6 is not the normal human body temperature - and probably never was.
So how did this little scarlet line become sacred in the first place, and why has it fallen out of favor?
It's a tale that begins more than 150 years ago at a university hospital ward in Leipzig, Germany - and ends here in Baltimore, at the door of Dr. Philip Mackowiak.
Mackowiak, 59, is an infectious disease specialist and fever researcher at the Veterans Affairs Medical Center on North Greene Street. In the early 1990s, he became increasingly suspicious about the textbook value for the average oral body temperature, since it rarely reflected what he saw each day in his exam room.
"Every now and then, 98.6 would come up," he recalls. But only now and then. "It just didn't seem to make sense."
His suspicion eventually led him to conduct the first major examination of body temperature in more than a century. But he didn't stop there. An amateur medical historian who organizes an annual seminar to diagnose fatal diseases of the famous, Mackowiak decided to ferret out the number's obscure origins.
Despite its bedrock standing, "I had no idea where it came from," he says. And he suspected that most of his colleagues didn't, either.
Finding the answer would eventually require hours leafing through musty journals and century-old German medical tomes. He also wound up doing some unexpected historical sleuthing. For example, when Mackowiak heard about a 150-year-old thermometer suspected of playing a role in the 98.6 story, he gingerly toted it from Philadelphia to his Baltimore lab for testing.
In the end, Mackowiak discovered - perhaps not surprisingly - that the history of 98.6 is intimately intertwined with the thermometer's arrival in medicine itself.
