Measuring body temperature is a common practice to assess overall health, and the axillary, or underarm, method offers a convenient and non-invasive approach. This technique is particularly favored for infants and young children, where other methods might be more intrusive or challenging to perform. While axillary temperature readings are widely used, they generally provide a lower measurement compared to the body’s internal, or core, temperature. Understanding how to accurately interpret these readings is important for parents and caregivers.
The Adjustment for Axillary Temperature
When taking an underarm temperature, an adjustment is typically made to better estimate the body’s core temperature. Healthcare professionals generally advise adding 0.5 to 1 degree Fahrenheit (or 0.3 to 0.6 degrees Celsius) to the axillary measurement. This adjustment helps bridge the difference between the armpit’s surface temperature and the internal body temperature. This adjusted number provides an estimation rather than a precise core temperature.
For adults, the average axillary temperature typically ranges from 95 to 98.47 degrees Fahrenheit (35.01 to 36.93 degrees Celsius). Infants commonly show an underarm temperature around 98.24 degrees Fahrenheit (36.8 degrees Celsius). Applying the recommended adjustment, an estimated normal core body temperature derived from an axillary reading would generally fall within approximately 97.6°F to 99.6°F (36.4°C to 37.6°C).
Understanding Axillary Temperature Readings
Axillary temperature is typically lower than core body temperature due to physiological factors. The armpit is a surface area of the body, and its temperature is naturally cooler than the internal organs. The skin dissipates heat, which can lead to a lower surface reading. Compared to internal areas, the armpit receives less consistent blood flow, which also contributes to its cooler temperature. External factors can also influence axillary readings, such as the surrounding room temperature or recent physical activity.
Best Practices for Accurate Axillary Readings
Achieving an accurate axillary temperature reading involves following specific steps when using a digital thermometer. Ensure the armpit is dry, as moisture can affect the measurement. Position the tip of the thermometer in the center of the armpit, making sure it touches the skin directly and not clothing. Hold the arm down firmly against the body, keeping the thermometer securely in place until it beeps. The thermometer usually signals when the reading is complete, typically within about a minute.
While convenient and non-invasive, axillary temperature measurements are generally considered less accurate than those taken orally, rectally, or tympanically (in the ear). Despite these limitations, the axillary method is appropriate and safe for initial screening, especially in young children, or when other measurement sites are impractical. It offers a comfortable way to check for temperature changes without discomfort. If there are concerns about a definitive temperature reading, or if a fever is suspected, consulting a healthcare professional is always advisable.