Temperature

Temperature Measurement of body temp. aims to obtain a representative average temperature of core body tissues. Because surface temperature varies depending on blood flow to the skin and the amount of heat lost to the external environment, sites reflecting core temperatures are more reliable indicators of body temperature. The best site to use varies with the age of the patient, the situation, and agency policy. To ensure an accurate temperature reading, you must use the thermometer properly and document the site correctly. For repeated measurements or comparison of measurements over time, be sure to use the same site each time. There is no single temperature reading that is “normal” for all patients, although many consider an oral temperature of 98.6° F (37° C) the norm. Age, exercise, hormones, stress, environmental temperature, time of day, body site, and medications can all influence body temperature. In general, an oral body-temperature range of 96.8° F to 100.4° F (36.2° C to 38° C) is acceptable. A rectal temperature is usually 0.9° F (0.5° C) higher than an oral temperature, and axillary and tympanic temperatures are usually 0.9° F (0.5° C) lower than an oral temperature. Agency policy usually specifies whether to document a temperature reading in degrees Fahrenheit or degrees Celsius. Many thermometers can convert a temperature reading from one measurement scale to the other. If you use one that does not have this feature, convert degrees F to degrees C by subtracting 32 and then multiplying by 5/9; convert degrees C to degrees F by multiplying by 9/5 and then adding 32. Several different types of thermometers are available for measuring temperature. The most common types are electronic thermometers, tympanic thermometers, and temporal thermometers. The chemical-dot or strip thermometer is less commonly used than the others. Most healthcare facilities no longer use mercury thermometers because of the environmental hazards that mercury-containing devices pose. An electronic thermometer consists of a rechargeable, battery-powered display unit, a thin wire cord, and two temperature probes. The blue-tipped probe measures oral temperature; the red-tipped probe measures rectal temperature. A single-use, disposable plastic sheath covers the appropriate probe during use. An audible signal indicates that the device has completed its measurement, after which the temperature reading appears on the digital display. Placing the probe back in the display unit resets the device. Measuring temperature - Electronic, oral Provide privacy and explain the procedure to the patient. Place the covered temperature probe under the patient's tongue in the posterior sublingual pocket. Instruct the patient to close the lips gently around the probe and to keep the mouth closed until the temperature has been measured. Remind the patient not to bite down on the temperature probe. When the audible signal indicates that the temperature has been measured, remove the probe and read the digital display. Discard the disposable cover and document the results. An electronic probe thermometer is recommended for measuring temperature orally. The temperature is indicated on a digital display that is easy to read. Electronic probe thermometers can also be used for rectal and axillary readings. Always use a protective cover over an oral electronic thermometer's probe. Place the probe in the sublingual pocket and instruct the patient to close the mouth, breathe through the nose, and hold the probe in place with the lips without biting down. Wait for the device to beep before reading the temperature on the display. Measuring temperature - Electronic, axillary Provide privacy and explain the procedure to the patient. Assist the patient to a sitting position and move the bed linens, gown, or other clothing to expose the patient's axilla. Dry the axilla, if needed. Place the covered temperature probe under the patient's arm in the center of the axilla. Leave the thermometer probe in place until the audible signal indicates that the temperature has been measured. The temperature reading appears on the digital display. Discard the disposable cover and document the results. Because the axilla is on the outside of the body, a temperature reading from the axillary site is generally 0.9° F (0.5° C) lower than that from the mouth or ear. A normal reading for an axillary temperature is between 96.6° F (35.9° C) and 98° F (36.7° C). Factors that influence an axillary temperature are the time of day the temperature is measured and the patient's level of activity prior to temperature measurement. Measuring temperature - Tympanic Provide privacy and explain the procedure to the patient. Gently push the disposable plastic cover over the tip of the electronic thermometer until the cover locks into place. Gently pull the pinna, also called the auricle, back, up, and out, and insert the tip of the covered thermometer probe into the patient's ear canal. Leave the thermometer probe in place until the audible signal indicates that the temperature has been measured. The temperature reading appears on the digital display. Discard the disposable cover and document the results. The cone-shaped tip of the tympanic thermometer uses infrared technology to measure body temperature from heat of the eardrum (tympanic membrane) and the surrounding tissue. That heat is then converted to a digital reading. Most tympanic devices produce an easy-to-read digital display quickly. Many tympanic thermometers provide Celsius and Fahrenheit conversions and reading equivalents for oral and rectal temperatures. Measuring temperature - Temporal Provide privacy and explain the procedure to the patient. Remove the protective cap and wipe the lens of the scanning device with an alcohol swab to make sure it is clean. Position the probe flat on the center of the patient's forehead at midpoint between the hairline and the eyebrow. Press the scan button and slowly slide the thermometer across the forehead and just behind the ear. Some arterial-scan thermometers recommend sliding the device from the forehead to just below the ear lobe. Release the scan button and read the display. The temporal artery is an excellent location for measuring temperature as it is suitable for all ages and poses no risk of injury for the patient or for the clinician. The scan across the forehead is gentle, comfortable, and acceptable. Arterial temperature is close to rectal temperature, but it is nearly 1° F (0.5° C) higher than an oral temperature, and 2° F (1° C) higher than an axillary temperature.