From UPSC perspective, the following things are important :
Prelims level : Euthermia
Mains level : Not Much
Euthermia refers to normal body temperature. The thermometer reading of 98.6°F has been a gold standard for a century and a half, ever since a German doctor laid it down as the “normal” body temperature. A new research has found that body temperatures have, in fact, been declining over the last two centuries.
Why we follow 98.6°F?
- In 1851, Carl Reinhold August Wunderlich pioneered the use of the clinical thermometer.
- It was a rod a foot long, which he would stick under the armpits of patients at the hospital attached with Leipzig University, and then wait for 15 minutes (some accounts say 20 minutes) for the temperature to register.
- He took over a million measurements of 25,000 patients, and published his findings in a book in 1868, in which he concluded that the average human body temperature is 98.6°F.
- Most modern scientists feel Wunderlich’s experiments were flawed, and his equipment inaccurate.
- Another study concluded that the average human body temperature is closer to 98.2°F, and suggested that the 98.6°F benchmark be discarded.
The body is cooler
- The Stanford University the researchers confirmed some known trends — body temperature is higher in younger people, in women, in larger bodies and at later times of the day.
- Additionally, they found that the bodies of men born in the early to mid-1990s is on average 1.06°F cooler than those of men born in the early 1800s.
- And the body temperature of women born in the early to mid-1990s is on average 0.58°F lower than that of women born in the 1890s.
- The calculations from the research correspond to a decrease in body temperature of 0.05°F every decade.
Why there’s decrease in body temperature?
- The researchers have proposed that the decrease in body temperature is the result of changes in the environment over the past 200 years, which have in turn driven physiological changes.
- The decrease in average body temperature in the US, they said, could be explained by a reduction in metabolic rate, or the amount of energy being used.
- The environment that we’re living in has changed, including the temperature in our homes, our contact with microorganisms and the food that we have access to.
- Actually the human body is changing physiologically.
So what’s the normal temperature?
- The strong influences of age, time of day, and genders determine the healthy body temperature.