A Critical Appraisal of 98.6°F, the Upper Limit of the Normal Body Temperature, and Other Legacies of Carl Reinhold August Wunderlich

Abstract

Thirty-seven degrees centigrade (98.6 degrees F) should be abandoned as a concept relevant to clinical thermometry; 37.2 degrees C (98.9 degrees F) in the early morning and 37.7 degrees C (99.9 degrees F) overall should be regarded as the upper limit of the normal oral temperature range in healthy adults aged 40 years or younger, and several of Wunderlich's other cherished dictums should be revised.

Fever, fever patterns and diseases called ‘fever’ – A review

“…However, most authors [2][3][4] are in agreement with a study in which modern calibrated thermometers were used to measure 700 baseline-oral temperatures of 148 middle aged healthy adults of different races [10]. In this study, the mean oral temperature was 36.8 ± 0.4 • C (98.2 • F) and body temperature exhibited a circadian rhythm with 99th percentile of the population having maximum morning (at 6.00 am) of 37.2 • C and maximum afternoon (at 4.00 pm) temperature of 37.7 • C. Thus, on the basis of this study data, fever in healthy middle aged adults may be defined as early morning oral temperature of >37.2 • C (>99 • F) or a temperature of >37.7 • C (>100 • F) at anytime during the day.…”

A hot topic

“…Mean core body temperature is tightly regulated and ranges between 36.5-37.5°C, 27 while skin temperature is significantly lower and averages around 33°C. 28 Temperature of the external environment, as well as internal heat produced by increased metabolism, can perturb the normothermic state.…”

Fiebre: Conflictode escalas

“…En su apartado de unidades de medida, señalan que éstas deben indicarse en unidades del sistema métrico y la temperatura en grados centígrados, pero algunos países, especialmente anglosajones, siguen utilizando en la práctica diaria la escala Fahrenheit y la traducen en sus trabajos al SI. Un estudio reciente del Veterans Affairs Maryland Health Care Center ha tenido gran trascendencia en el número de citaciones en otros trabajos y referencias posteriores 4 . Se estudiaron 148 sujetos sanos, entre 18 y 40 años, en quienes se realizaron 700 tomas de temperatura bucal basal en dos días consecutivos.…”