Why Doctors Order Rectal Temperatures for Adults

When it comes to taking a patient’s temperature, a rectal measurement remains a vital and highly accurate method, especially for adults. Despite the advancement of various temperature-taking devices, the rectal region remains the best option for obtaining a precise reading.

Accuracy vs Convenience

While the rectal method may be considered less convenient by some, its accuracy makes it indispensable in certain scenarios. In cases where a highly accurate reading of core body temperature is crucial, such as during the monitoring of severe infections or the risk of infection, a rectal temperature reading is the preferred method. Oral and axillary temperature readings, for instance, are notoriously inaccurate and less reliable, which is why they are often avoided or considered secondary.

Preference Over Peripheral Methods

In situations where peripheral circulation is compromised, a surface temperature reading, such as from the temporal artery or tympanic membrane, might not accurately reflect the core body temperature. This is because these methods can be influenced by external factors like poor blood flow or cooling effects on the skin’s surface. For instance, if a patient’s peripheral circulation is “clamped down,” a temporal artery scan might show an artificially low temperature.

Rectal Temperatures in Emergency Scenarios

When dealing with scenarios that require a deep understanding of the patient's internal physiology, such as suspected serious hypothermia or the need to measure the temperature of the abdominal cavity, a rectal probe with a thermistor is the tool of choice. In some extreme cases, even invasive measures like opening the abdomen and pouring in hot salt-water to raise the temperature can be necessary, highlighting the importance of accurate core body temperature readings.

Common Reasons for Rectal Temperatures

There are several reasons why a doctor might order a rectal temperature reading for an adult. Some of these reasons include:

To accurately track a patient's temperature changes over time, which is critical in cases of infections or other medical emergencies. To rule out serious conditions, such as Hodgkin's lymphoma, that might present with a fever but are not the most likely cause. To differentiate between mild illnesses and more severe conditions, as a high fever in an adult might indicate a variety of causes including suspected hypothermia.

It's important to note that while rectal temperatures remain the gold standard for core body temperature readings, they are not always the most convenient option. However, their accuracy makes them invaluable in critical medical scenarios where precise measurements are necessary.

Disclaimer: This answer is not a substitute for professional medical advice. This answer is for general informational purposes only and is not a substitute for professional medical advice. If you think you may have a medical emergency, call your doctor or in the United States, dial 911 immediately. Always seek the advice of your doctor before starting or changing treatment.