Where to Take Temperature with an Infrared Thermometer: A Guide to Accuracy
The most accurate places to take temperature with an infrared thermometer are the forehead (temporal artery) and the inner ear (tympanic membrane), but proper technique is crucial for reliable readings.
Introduction: The Rise of the Infrared Thermometer
Infrared (IR) thermometers have become ubiquitous tools for quickly and non-invasively measuring body temperature. Their speed, ease of use, and non-contact nature make them ideal for screening large groups of people, monitoring infants and children, and generally avoiding the discomfort and hygiene concerns associated with traditional thermometers. However, understanding where to aim the thermometer and how to use it correctly is paramount to obtaining accurate and reliable temperature readings. This article provides a comprehensive guide to using infrared thermometers effectively.
Benefits of Infrared Thermometry
Infrared thermometers offer several advantages over traditional methods:
- Speed: Readings are typically obtained in seconds.
- Non-Contact: Minimizes the risk of cross-contamination.
- Ease of Use: Simple operation makes them accessible to a wide range of users.
- Convenience: Can be used on infants, children, and adults without discomfort.
- Versatility: Many models can also measure surface temperatures.
Target Areas for Infrared Temperature Measurement
The choice of target area depends on the type of thermometer and the individual being measured. Commonly used areas include:
- Forehead (Temporal Artery): Measures the temperature of the temporal artery, a major blood vessel in the forehead.
- Inner Ear (Tympanic Membrane): Measures the temperature of the eardrum, which shares a blood supply with the brain.
- Armpit (Axillary): Although not as accurate as the forehead or ear, some IR thermometers are designed for axillary use.
- Other Surfaces: Many IR thermometers can measure the temperature of objects like baby bottles or food.
The Forehead Measurement Process
The forehead, specifically targeting the temporal artery, is a popular and relatively accurate site for infrared temperature measurement. Here’s how to do it correctly:
- Select the Right Thermometer: Ensure your thermometer is specifically designed for forehead measurement.
- Positioning: Hold the thermometer a short distance (typically 1-3 cm) from the center of the forehead. Refer to your thermometer’s manual for the specific distance.
- Scanning (if required): Some thermometers require a slow, steady scan across the forehead from the center to the hairline. Follow the manufacturer’s instructions.
- Environmental Considerations: Avoid taking readings immediately after someone has been exposed to direct sunlight, extreme temperatures, or vigorous activity. Allow time for acclimatization.
- Hair: Ensure the forehead is free of hair or sweat, as these can interfere with the reading.
The Ear Measurement Process
Using an infrared thermometer in the ear (tympanic membrane) requires careful technique:
- Select the Right Thermometer: Use a thermometer specifically designed for ear measurement. These often have a narrow probe.
- Positioning: Gently pull the ear up and back (for adults) or down and back (for children under 3) to straighten the ear canal.
- Insertion: Carefully insert the probe into the ear canal, ensuring a tight seal.
- Activation: Press the button to take the measurement.
- Hygiene: Use a disposable probe cover for each measurement to prevent cross-contamination.
Common Mistakes and How to Avoid Them
Inaccurate readings are often the result of incorrect technique or environmental factors. Here are some common pitfalls:
- Incorrect Distance: Holding the thermometer too far from the forehead can significantly affect the reading. Always follow the manufacturer’s recommended distance.
- Sweat or Hair: Sweat or hair on the forehead can interfere with the infrared signal. Ensure the forehead is clean and dry.
- Earwax: Excessive earwax can block the infrared sensor and lead to inaccurate readings.
- Environmental Factors: Taking readings in drafty rooms or immediately after exposure to extreme temperatures can skew the results.
- Thermometer Malfunction: Ensure the thermometer is properly calibrated and functioning correctly. Replace batteries regularly.
- Using the Wrong Mode: Many thermometers have different modes for body temperature and surface temperature. Make sure you are using the correct mode.
Temperature Variations and Considerations
Normal body temperature can vary depending on age, activity level, and time of day. Infants and children often have slightly higher temperatures than adults. Understanding these variations is crucial for interpreting readings accurately. Furthermore, infrared thermometers might produce slightly different results than oral or rectal thermometers. A table comparing average temperature ranges by method is shown below:
| Measurement Method | Average Temperature (°F) |
|---|---|
| Oral | 98.6 |
| Rectal | 99.6 |
| Axillary | 97.6 |
| Temporal (Forehead) | 98.0 – 99.0 (varies) |
| Tympanic (Ear) | 99.5 |
Calibration and Maintenance
Proper calibration and maintenance are essential for ensuring the accuracy of your infrared thermometer. Follow the manufacturer’s instructions for calibration procedures. Regularly clean the sensor lens with a soft, dry cloth. Store the thermometer in a cool, dry place and protect it from extreme temperatures and humidity.
Frequently Asked Questions (FAQs)
How accurate are infrared thermometers compared to traditional thermometers?
Infrared thermometers, when used correctly, can be relatively accurate, though they may not be as precise as traditional oral or rectal thermometers. Accuracy depends on factors such as the quality of the thermometer, the measurement technique, and environmental conditions.
Can infrared thermometers detect a fever even if someone isn’t showing symptoms?
Yes, infrared thermometers can detect a fever even if someone isn’t showing other symptoms. Fever is an objective measurement that indicates an elevated body temperature, regardless of the presence or absence of subjective symptoms.
Are there any health risks associated with using infrared thermometers?
Infrared thermometers are considered safe for use. They do not emit radiation; they simply detect infrared energy emitted by the body. There are no known health risks associated with their proper use.
How often should I calibrate my infrared thermometer?
Follow the manufacturer’s recommendations for calibration. Some thermometers require regular calibration, while others may only need calibration if you suspect inaccuracies. It’s always a good idea to periodically check your thermometer against a known standard.
Can I use an infrared thermometer on a baby?
Yes, infrared thermometers are commonly used on babies. Forehead and ear thermometers are particularly suitable for infants due to their non-invasive nature. Always follow the manufacturer’s instructions for use on infants and young children.
What if I get different readings on different parts of the forehead?
Slight variations in temperature across the forehead are normal. If you’re using a scanning thermometer, ensure you’re scanning slowly and steadily. If you’re getting significantly different readings, recheck the thermometer’s positioning and ensure the forehead is clean and dry.
Why does my infrared thermometer sometimes show a “low” reading?
A “low” reading can be caused by various factors, including incorrect distance, environmental conditions, a dirty sensor, or low batteries. Double-check your technique and the thermometer’s condition.
What is the “normal” temperature range when using an infrared thermometer?
The “normal” temperature range varies depending on the measurement location. Generally, a normal forehead temperature is around 98.0 – 99.0°F, while a normal ear temperature is around 99.5°F. Refer to your thermometer’s manual for specific guidelines.
How do environmental factors affect infrared thermometer readings?
Extreme temperatures, humidity, and drafts can all affect infrared thermometer readings. Avoid taking readings in drafty areas or immediately after someone has been exposed to extreme temperatures. Allow time for acclimatization before taking a measurement.
Can infrared thermometers be used to detect fevers in animals?
Some infrared thermometers can be used on animals, but it is important to consult with a veterinarian to determine the appropriate measurement location and normal temperature range for the specific animal.
How do I clean an infrared thermometer?
Clean the thermometer according to the manufacturer’s instructions. Typically, this involves wiping the sensor lens with a soft, dry cloth or using an alcohol wipe (isopropyl alcohol) if needed.
What should I do if I suspect my infrared thermometer is malfunctioning?
If you suspect your thermometer is malfunctioning, check the batteries, clean the sensor lens, and try recalibrating it if possible. If the problem persists, contact the manufacturer for assistance or consider replacing the thermometer.