Normal Armpit (Axillary) Body Temperature
Axillary temperature measurements are consistently 1.5–1.9°C below core body temperature and should not be relied upon for accurate temperature assessment in clinical practice. 1
Key Temperature Values
Expected Axillary Range
- Axillary temperatures typically measure 35.0–36.9°C (95.0–98.4°F) when extrapolated from oral temperature data, though this method has poor precision. 2
- The calculated normal range for axillary measurements is approximately 35.01–36.93°C, representing mean ± 2 standard deviations from research data. 2
Why Axillary Measurements Are Problematic
- Axillary measurements have up to 1°C variability and are among the least accurate temperature monitoring methods available. 1
- These measurements can be disturbed by external temperatures, local blood flow, and incorrect probe placement. 1
- Precision of axillary measurements is inferior to nasopharyngeal, esophageal, bladder, oral, and rectal methods. 1
Clinical Recommendations
Preferred Measurement Sites
For accurate temperature assessment, use oral or rectal measurements instead of axillary when central monitoring (pulmonary artery, bladder, or esophageal thermistors) is not available. 3, 4
- Oral temperatures are safe and convenient for alert, cooperative patients, with a normal range of 35.73–37.41°C (96.3–99.3°F). 2
- Rectal temperatures provide more accurate core estimates with a range of 36.32–37.76°C (97.4–100.0°F). 2
Important Clinical Caveats
- Individual baseline temperatures vary dramatically (ranging from 35.2°C to 37.4°C in healthy adults), making a single "normal" value inappropriate for all patients. 5
- Older adults (≥60 years) have temperatures averaging 0.23°C lower than younger adults, with many elderly individuals having baseline temperatures well below 37.0°C. 2, 6
- Women typically have slightly higher temperatures than men (approximately 0.2°C difference). 5, 7
Practical Approach
If axillary measurement must be used:
- Recognize that readings will underestimate core temperature by 1.5–1.9°C. 1
- Do not use axillary measurements for critical clinical decisions regarding fever or hypothermia. 3
- Consider any axillary reading above 36.5°C as potentially indicating fever (equivalent to oral temperature of ~38.0°C). 1
- Switch to oral or rectal measurement if accurate temperature assessment is needed for diagnosis or management. 3