Contributor: Chris Holmes, MD Educational Pearls: Dr. Carl Reinhold August Wunderlich, of the mid-1800s, was the first physician to suggest temperature was related to disease processes and his measurements set the 37˚C (98.6˚F) as the baseline temperature Thermometers were adapted to be sold to the public with guidelines for temperature measurement interpretation Taller and thinner individuals, anyone taking a temperature in the morning, and the elderly have decreased temperatures Temperature averages have been decreased and the actual average temperature appears to be closer to 97.5˚ currently References Wright WF. Early evolution of the thermometer and application to clinical medicine. J Therm Biol. 2016;56:18-30. doi:10.1016/j.jtherbio.2015.12.003 Geneva II, Cuzzo B, Fazili T, Javaid W. Normal Body Temperature: A Systematic Review. Open Forum Infect Dis. 2019;6(4):ofz032. Published 2019 Apr 9. doi:10.1093/ofid/ofz032 Chen W. Thermometry and interpretation of body temperature [published correction appears in Biomed Eng Lett. 2019 Feb 25;9(1):19]. Biomed Eng Lett. 2019;9(1):3-17. Published 2019 Feb 9. doi:10.1007/s13534-019-00102-2 Summarized by John Spartz, MS4 | Edited by Erik Verzemnieks, MD