A fever indicates an elevated body temperature. Monitoring body temperature provides valuable information about one’s health status, helping determine if the body’s immune system is engaged in fighting off a potential threat. Understanding how to accurately measure temperature is a foundational step in assessing well-being.
The Basics of Underarm Temperature
Underarm temperature, also known as axillary temperature, is a method of measuring body temperature by placing a thermometer in the armpit. This method is favored for its convenience and non-invasiveness, making it common for infants and young children. While generally considered a less accurate reflection of core body temperature compared to oral or rectal measurements, it serves as a useful screening tool. Axillary readings typically run slightly lower than oral or rectal temperatures, sometimes by 0.5 to 1 degree Fahrenheit.
A normal axillary temperature for adults typically ranges between 95 and 98.47 degrees Fahrenheit (35.01 to 36.93 degrees Celsius). For infants, an average underarm temperature is around 98.24 degrees Fahrenheit (36.8 degrees Celsius). An underarm temperature of 99.0°F (37.2°C) or higher is generally considered a fever by this method. If an axillary reading suggests a fever, particularly in young children, healthcare providers may recommend confirming it with a more accurate method like a rectal temperature.
Taking an Underarm Temperature Correctly
A digital thermometer is recommended; glass mercury thermometers should be avoided due to safety concerns. Begin by ensuring the armpit is dry, as moisture can affect the reading. Turn on the digital thermometer, and if it has a protective cover, remove it.
Place the tip of the thermometer directly into the center of the armpit, ensuring it touches the skin and not clothing. Have the individual lower their arm and hold it snugly against their body, pressing it against the thermometer to keep it securely in place. Allow the thermometer to remain in place until it beeps, signaling completion, or for about 4 to 5 minutes if it doesn’t beep. After removing the thermometer, read the displayed temperature and clean the device with soap and water or rubbing alcohol before storing it.
What to Do About an Underarm Fever
When an underarm temperature indicates a fever, the course of action depends on the individual’s age and accompanying symptoms. For infants younger than 3 months, any fever, especially a rectal temperature of 100.4°F (38°C) or higher, warrants immediate medical attention. For children between 3 and 6 months, a fever of 102.2°F (39°C) or higher, or a lower temperature accompanied by irritability or poor feeding, requires a call to a healthcare provider. Older children with a fever that lasts more than three days, or one that is 104°F (40°C) or higher, requires evaluation by a doctor.
Adults typically tolerate fevers better, but seek medical attention for temperatures exceeding 103°F (39.4°C) or those lasting more than three days without improvement. Regardless of age, seek immediate medical care if a fever is accompanied by concerning symptoms:
Stiff neck
Severe headache
Rash
Difficulty breathing
Persistent vomiting
Confusion
Seizures
While awaiting medical advice, general comfort measures include encouraging fluid intake to prevent dehydration, dressing in light clothing, and ensuring adequate rest. Over-the-counter medications like acetaminophen or ibuprofen can help reduce discomfort in older children and adults, but always follow dosage instructions and consult a doctor, especially for infants or individuals with other health conditions.