With time many different studies came up telling about human body temperatures. Meanwhile a team from Stanford University analysed three sets of data from different ages and came up with a result showing the reasons for change in human body temperature not merely because of fever, cold or any virus but certain other factors…
"Our body temperature is not what people think it is”: Dr. Julie Parsonnet

New Delhi: Human body has been studied for a very long time, but with time, physiological pressure changes and the normal body temperature has changed and it has dropped since the 19th century. The recent studies also highlight the potential causes of these alterations. Body temperature can not only change because of fever, cold or any virus but your lifestyle, age, habits and ambient temperature also matters, these factors influence our body heat. Temperature of your body is also a determinant of metabolic heath, the authors of recent study explain, that human body temperatures indicates metabolic rate, of which some are linked with body size and longevity.

What exactly is your normal body temperature?

A German physician, in 1851, called Carl Reinhold August Wunderlich, surveyed 25,000 people residing in a single city and established that 37 degree Celsius (98.6°F) is the standard human body temperature. Though, recent surveys and studies establish that the average body temperature nowadays is lower. As for instance, a study of nearly 250,000 temperature measurements of more than 35,000 individuals in the United Kingdom is 36.6°C (97.88°F) on an average. Is it possible that this change is because of a change in measurement tools? Or, is it the reflection of higher life expectancy and better overall health?

For the investigation, a team from Stanford University’s Division of Infectious Diseases and Geographic Medicine, in California went out, where they hypothesised that “the differences observed in temperature between the 19th century and today are real and that the change over time provides important physiological clues to alterations in human health and longevity since the industrial revolution.” The team work appeared in the journal eLife.

Historic trends in body temperature says:

The hypothesis were analyzed by researchers from three datasets:

  1. The data set from 1862-1930 from Union Army veterans of the Civil War was studied.

  2. The second dataset was from the United States National Health and Nutrition Examination Survey I, time period was 1971-1975.

  3. And the third dataset was from Stanford Translational Research Integrated Database Environment, it consisted of records of individuals who received healthcare through Stanford between 2001-2017.

Overall, researchers had access to 677,423 temperature measurements nearly, forming a model of change over time. 

Body temperature which changed shows a downfall:

“What everybody grew up learning, which is that our normal temperature is 37 degree celsius, is wrong.” said by Dr. Julie Parsonnet.

The findings done by researchers’ include:

  1. On an average 0.59 degree celsius is lower than that of men born in the early 19th century.

  2. The same way women’s body temperature dropped by 0.32 degree celsius from the 1890s to today.

  3. The average of 0.03 degree celsius decreased overall with every decade.

The team of Stanford University also cross examined if the differences were because of change in temperature testing machines, assuming that doctors in each historical period were in general using the same type of thermometers. The results of the analysis reflected the changes in the combined data.  “Our temperature is not what people think it is,” says Dr. Julie Parsonnet, a professor of medicine, health research, and policy, and the senior author of the study. So the overall combined results showed that with time, gender and physiological status body temperature can change too, the researchers do not advise updating the standards.