Nehaveigur

Average body temperatures have fallen since we started measuring in the 19th century. We know this from temperature readings going all the way back to 1840. This effect even holds within cohorts, making faulty measurements by badly calibrated thermometers unlikely as a cause. The trend of declining body temperatures initially observed in 2020 has since been replicated. Here is one observation from a Bolivian population. Unfortunately, replication hasn’t been attempted in other cohorts that would be well suited for this purpose, including the Framingham cohort, which follows thousands of people since 1948 and would have meticulous temperature measurements. Falling body temperatures are a marker of a falling basal metabolic rate, but what causes this isn’t known either.