At the Core of Accuracy: Rethinking Temperature Measurement in Clinical Practice

October 22, 2025

Accurate, fast and non-invasive—three words every clinician wants to hear when it comes to vital signs acquisition. Temperature is often the first indicator of physiological change, yet how we measure it can vary significantly. As clinicians, we know that temperature measurement is not one-size-fits-all. The site and method we choose can influence the reliability of the result and, in turn, impact clinical decision making.

There are several non-invasive methods used to obtain temperature readings, including oral, axillary, tympanic and temporal artery. However, it’s important to remember that not all these methods measure core temperature, and depending on the site, the measurement of body temperature can vary by as much as 1°C.1 In fast-paced or high-acuity environments, that difference can affect how and when we respond to a patient’s condition. This variance is important in critical settings where early detection of fever or hypothermia may influence isolation protocols, diagnostic pathways or interventions.

This blog explores how the Exergen® TemporalScanner® functions as a clinically relevant tool for obtaining accurate core temperature in a variety of patient care settings. Through a clinical lens, we’ll examine how temporal artery thermometry compares to other noninvasive methods, why core temperature matters in everyday decision-making, and how small differences in technique or modality can influence the bigger clinical picture.

Why is core temperature important?

Core temperature reflects the temperature of the internal organs. In most clinical settings, access to true core temperature has historically been limited to critical care, where rectal probes or arterial lines are used. These methods are invasive and not practical for routine monitoring. Thermoregulatory changes in disease and injury alter the temperature of the body. Thus, the purpose of the core temperature measurement is to obtain the accurate measure of the organs and the blood supply. When we detect subtle shifts in core temperature, we can intervene earlier, whether that means investigating infection, adjusting treatment or escalating care. Oral and axillary readings, while useful, are often influenced by environmental factors, recent intake or patient cooperation. Core temperature provides a clearer clinical signal.

In practice, fever plays a key role in decision-making. Do I call the doctor? Do we order labs? Start antibiotics? Isolate the patient? This alters and directs the next steps. That’s why accuracy is non-negotiable.

Technique Counts

Using any device correctly is just as important as choosing the right one. For the Exergen TemporalScanner, proper technique involves:

• Placing the probe on the center of the forehead.

• Pressing and holding the scan button.

• Gliding it across the forehead to the hairline in a straight path.

• While still holding the button, lifting the probe and briefly touching the skin just behind the earlobe to verify the result.

What stands out clinically using the Exergen TemporalScanner thermometer?

1. Quick, one-handed use
   Time matters. Temporal artery thermometers allow for quick, accurate readings in seconds, which is ideal in fast-paced environments. The one-handed operation allows for efficient multitasking.

2. Non-invasive and minimal disruptions
   The scanner doesn’t require insertion or cause disruption. It allows clinicians to assess temperature without causing distress or interrupting care activities or patient sleep.

3. Clinically validated
   Using the Exergen TemporalScanner thermometer as a core temperature measurement tool is backed by clinical evidence.

4. Reduces risk of cross-contamination
   With no need for internal contact, the risk of contamination is lessened. While probe covers may not be required for every patient—depending on your facility’s infection prevention protocols—disposable covers are available. Adherence to facility specific infection control policies is essential.

5. Appropriate for all age groups
   This method can be used across all patient populations.

"During my years as a pediatric bedside nurse, I found this tool particularly helpful. Children often arrive at the hospital or clinic feeling anxious and scared. The use of this thermometer allowed me to quickly assess the patient's temperature without causing discomfort or waking a sleeping child."

Dustin Shadoan, BSN, RN

Best Practice for Accuracy

• Ensure the TemporalScanner is clean and disinfected per facility protocol. See the Exergen Instructions for Use for complete cleaning instructions.

• Use consistent technique: Full scan across the forehead to the hairline and then touch behind the ear lobe. Be sure to remove any hats or other material and push aside hair that may be in the way.

• Allow the device to acclimate to the room temperature before scanning and if moved between temperature environments.

• Always reference the Exergen TemporalScanner product manual for clarification on usage or troubleshooting.

• Know your thermometer: Read the instructions carefully so you know how to use, store and maintain it.

Since the onset of the COVID-19 pandemic, temperature monitoring has remained central to clinical screening and surveillance. But beyond public health protocols, temperature is a foundational component of in-office and bedside assessment. The method you choose to measure temperature should align with both the clinical context and the patient’s condition. While rectal probes and arterial lines provide direct core readings, they’re typically reserved for critical care or inpatient settings due to their invasive nature. In contrast, the Exergen TemporalScanner offers a noninvasive alternative that delivers core temperature accuracy backed by evidence. For clinicians working in fast-paced, varied environments, this can be a practical and reliable tool to evaluate core temperature. As always, understanding the strengths and limitations of each modality helps us make informed, patient-centered decisions for better outcomes.

About the Author

Dustin Shadoan is a dedicated Clinical Education Manager at Midmark Corporation, bringing a strong clinical background and a passion for healthcare education. With prior experience as a pediatric registered nurse in intensive care units and emergency departments, Dustin understands the critical needs of frontline providers. He is deeply committed to empowering healthcare professionals through engaging, evidence-based training initiatives that enhance patient outcomes and drive successful product adoption.

Exergen and TemporalScanner are trademarks of Exergen Corporation.