How should the thermometer be inserted when using an electric thermometer to take an oral temperature?

Be sure that you know how to operate the electric thermometer before using it to take a patient’s temperature.

Table of Contents Show

Properly Using Your Oral Thermometer
The difference between rectal and oral thermometers explained
Misconceptions

Information on how to operate the electric thermometer can usually be found in an operator’s manual kept on the unit or found in the unit’s SOP. Different types of electric thermometers have different operating procedures.

The steps given below are general in nature. Before using an unfamiliar electric thermometer, be sure to read the instructions pertaining to that thermometer.

a. Wash Hands.

Perform a patient care hand wash.

b. Gather Materials.

You will need the following items:

(1) Electric thermometer with oral (blue) color-coded temperature probe.

(2) Probe covers (usually found with electric thermometer).

(3) Watch or clock (with second hand, if possible).

(4) Pencil or pen.

(5) Something on which to write (usually a form or sheet of paper).

(6) An electrical outlet, unless the electric thermometer is battery-powered.

c. Verify That the Oral Route Should Be Used.

Any situation that would prevent you from taking a patient’s oral temperature with a glass thermometer will also prevent you from taking his oral temperature with an electric thermometer.

d. Verify Patient’s Identity.

Make sure that you are taking the temperature of the patient properly by checking the patient’s identification bracelet and bed card and/or asking the patient his name.

e. Prepare Thermometer.

Make sure that the electric thermometer is working and ready to use. Several electric thermometers indicate that they are ready for use by displaying an initial temperature reading, such as displaying a reading of 94.0o F, when the probe is removed from its resting place. If such a thermometer does not show a display, check the electrical outlet or batteries, as applicable.

f. Cover Probe.

Insert the oral probe into a probe cover. The exact procedure used will depend upon the operating instructions for the thermometer you are using. Normally, you will insert to probe into a box containing probe covers. The innermost cover will automatically attach to the probe. You should not allow the probe cover to touch anything before the probe is inserted into the patient’s mouth.

g. Tell Patient About Procedure.

Tell the patient that you are going to take his temperature and give additional instructions as needed.

h. Position the Probe.

Place the heat sensing part of the probe so that it is lying on top of one of the heat pockets. The procedures are basically the same as for taking an oral temperature with a glass thermometer.

(1) Tell the patient to open his mouth and lift his tongue.

(2) Place the end of the probe over one of the heat pocket.

(3) Tell the patient to relax his tongue and close his lips (not his teeth) over the probe.

(4) Do not let go of the probe. Keep holding the probe in place with your thumb and finger(s).

i. Wait for Signal.

Continue holding the probe in place in the patient’s mouth until the electric thermometer gives the signal that the patient’s temperature has been determined.

(1) Hold the probe so that it is steady (not moving) and is in constant contact with the tissue of the heat pocket.

(2) The signal that the patient’s temperature has been determined is usually a red light that lights upon the main body of the electric thermometer.

(3) The time required for the temperature to be determined depends upon the thermometer, but is usually less than 60 seconds.

j. Remove Probe.

When the machine signals that the patient’s temperature has been determined, ask the patient to open his mouth. When the patient releases his hold upon the probe, remove the probe from his mouth.

k. Read and Record Temperature.

Read the patient’s temperature from the display on the main body of the thermometer and record the reading. If the display is not a digital readout, record the temperature to the nearest two-tenths of a degree Fahrenheit (0.2º F) or to the nearest tenth of a degree Celsius (0.1º C), as appropriate.

l. Discard Probe Cover.

The probe cover is used only once. After you have recorded the temperature, discard the cover into a container (patient’s waste basket, etc.). Some electric thermometer are designed so that the probe cover is ejected from the probe when you hold the probe collar between your index and middle fingers, point the probe downward, and press on top of the probe with your thumb.

m. Return Probe to Its Resting Place.

In some electric thermometers, returning the probe to its resting place automatically turns off the thermometer and resets the thermometer so that it is ready for the next use.

h. Wash Hands.

Perform another patient care hand wash.

While taking your temperature with an oral thermometer may seem easy, it isn’t as straightforward as it looks. Simply sticking a thermometer into a person’s mouth might not give you accurate results you want, because different areas in the mouth give off varying levels of heat.

Exploring the idea behind the oral thermometer, its misconceptions and the proper procedure can help you to accurately determine whether your child or patient has a fever. Luckily, the right procedure is easy to do and doesn’t take any extra tools or materials apart from your thermometer.

Properly Using Your Oral Thermometer

Described below are the proper steps in taking an oral temperature reading. The steps are in bold, and additional information on what can go wrong follows after.

Do not drink or eat 15 minutes prior to taking a temperature reading. As mentioned before, food and drinks change oral temperature significantly, thus affecting accuracy.
Do not breathe heavily through the mouth prior to taking temperature. Breathing through the mouth may lower the temperature of the mouth tissue, resulting in inaccurate readings.
Position the thermometer in the correct area, as close to the center as possible, under the tongue. The areas of the lower jaw next to the lower molars are heat pockets. Sticking the sensor or probe into this area is essential to getting the closest oral temp measurement.
Ensure there is no air left in the mouth while keeping the thermometer in place. Air in the mouth will cause temperature differences in the mouth tissue, making readings inaccurate.
Wait at least 20 seconds even if the thermometer indicates it is already ready. You may also measure twice. The metal probe or sensor’s temperature will first cool down the mouth tissue, so the tissue will need more time to go back up to body temperature.
Add several tenths of degrees to the temperature. When on a threshold of a fever, it is better to confirm the temperature by doing a rectal measurement just to be sure.

Understanding the things that can go wrong when using an oral thermometer is essential in getting the closest possible reading. You can take more than two readings to ensure that you get an average measurement of the oral temperature.

The difference between rectal and oral thermometers explained

You’ve seen it in cartoons or movies; Mickey Mouse with a thermometer sticking out of his mouth and an ice bag on his head. Using an oral thermometer is the most common way of measuring body temperature. It is more convenient compared to rectal measurements, though the latter is may be closer to your core thermometer. The idea is to insert the thermometer sensor or probe into the mouth, wait for a minute and get the exact temp reading.

Misconceptions

Body temperature is the same throughout, regardless of the body part being measured.

False. Physicians advise not to measure a young child’s temperature orally, since there are external factors that drastically affect the readings. For instance, children develop higher temperatures with activities milder than exercise, such as playing. Rectal temperature measurements are most accurate for young children. Furthermore, there are significant differences in temperature reading in different key areas of the body. Rectal temps can be 7 °F (3°C) higher than oral temps, while tympanic measurements can be 5.5 °F (2.5°C) higher than oral.

Taking oral temperatures requires simply sticking the thermometer in the mouth and taking a reading after a minute.

False. The thermometer sensor has to be in a specific area and requires specific conditions to result in accurate readings. While oral, rectal, gut and core body temperatures can slightly differ, they are well-correlated and oral temperature is lowest of the four. Furthermore, oral temperature is the most influenced by outside factors like drinking, chewing, smoking and breathing through the mouth. Intake of cold drinks and food will lower oral temps, while hot counterparts do the opposite.

Body temperature is constant, all day long.

False. While keeping temperature constant is part of what keeps humans at optimum operating temperature, no human always has the exact same body temperature throughout the day. Temperatures rise and fall regularly, helping to control a person’s circadian rhythm.

Inaccurate readings are due only because of low quality thermometers.

This is only 30% true. It is likely that the readings are off because the procedure is wrong. Make sure you are buying a quality thermometer.

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