Is a consistently normal body temperature of 37°C?

Under normal circumstances, the average axillary (underarm) temperature in adults ranges from 36.0°C to 37.0°C. However, body temperature varies depending on factors such as age, time of day (circadian rhythm), and sex. So, is a consistently recorded temperature of 37°C considered normal? Below, we provide a detailed explanation.

Is a persistent body temperature of 37°C normal?

A temperature of 37°C does not indicate fever. In adults, the normal oral (sublingual) temperature typically ranges from 36.3°C to 37.2°C; the normal axillary temperature ranges from 36.0°C to 37.0°C; and the normal rectal temperature ranges from 36.6°C to 37.6°C. Therefore, a temperature of 37°C falls within the normal range and does not constitute fever—there is no need for excessive concern.

What constitutes a normal body temperature?

1. Normal body temperature in adults

Body temperature typically reaches its lowest point between 2:00 AM and 5:00 AM and peaks between 5:00 PM and 7:00 PM. The diurnal variation should be less than 0.8°C. Additionally, women generally have an average body temperature approximately 0.35°C higher than men. The typical normal temperature ranges for adults measured orally, rectally, and axillary are as follows:

(1) Oral (sublingual) temperature: 36.3°C–37.2°C.

(2) Rectal temperature: 36.5°C–37.7°C—approximately 0.2°C–0.5°C higher than oral temperature.

(3) Axillary temperature: 36.0°C–37.0°C—approximately 0.3°C–0.6°C lower than oral temperature.

In adults, fever is defined as an oral temperature exceeding 37.6°C or an axillary temperature exceeding 37.3°C. Temperatures between 37.3°C and 38.0°C indicate low-grade fever; 38.0°C–39.0°C, moderate fever; 39.0°C–41.0°C, high fever; and temperatures above 41.0°C, hyperpyrexia.

2. Normal body temperature in children

Children’s normal body temperature tends to be slightly higher than that of adults, and it varies with age—generally, younger children have relatively higher baseline temperatures. Using oral, rectal, and axillary measurements as reference points, the typical normal temperature ranges for children are:

(1) Rectal temperature: 36.5°C–37.5°C.

(2) Oral temperature: 36.2°C–37.3°C.

(3) Axillary temperature: 35.9°C–37.2°C.

Fever in children is defined as a temperature exceeding the upper limit of the normal range by ≥0.5°C. Temperatures below 38.0°C are classified as low-grade fever; those above 39.0°C as high fever; and temperatures exceeding 41.0°C as hyperpyrexia.

The above provides an overview addressing whether a persistently recorded temperature of 37°C is normal. A temperature of 37°C does not indicate fever—whether measured axillary, orally, or rectally, it remains within the normal physiological range. We hope this information proves helpful.