Is it accurate to measure body temperature under the armpit when there is sweat?

Body temperature readings taken under the armpit are generally inaccurate when there is sweat present. It is recommended to wipe away the sweat with a towel and wait several minutes before measuring body temperature again.

Temperature measurement is useful for the prevention and diagnosis of clinical diseases. In most cases, body temperature is measured under the armpit, where the normal range is 36–37°C. However, when there is sweat in the armpit, surface body heat evaporates along with the sweat, leading to a lower temperature reading that does not reflect the body's actual internal temperature. Additionally, sweat may cause slippage between the thermometer and the skin, impairing proper heat transfer and resulting in measurement errors, which could affect disease assessment. Therefore, armpit temperature measurements taken in the presence of sweat are usually unreliable.

When measuring temperature under the armpit, if there is sweat present, it is advisable to use alternative methods such as oral or rectal temperature measurement. If the temperature exceeds the normal range, fever may be present, and patients are advised to seek timely medical evaluation at a hospital to determine the underlying cause and receive appropriate treatment.