Body temperature is an important vital sign, and helps healthcare professionals quickly determine a patient’s medical situation. In pediatric care, a normal or subnormal temperature reveals a normal condition, a simple fever, or a severe infection.
Measuring body temperature is a crucial diagnostic skill for healthcare professionals, such as nurses and medical assistants. Thermometer options to measure a patient’s temperature include oral, temporal, tympanic, and rectal thermometers.
Taking a temperature seems like a simple, straightforward task for most healthcare professionals; however, deciding which type of thermometer device to use for children can become a complicated decision between the parent and health professional.
Types of Thermometers
Oral Thermometry
Oral thermometers measure the temperature associated with the lingual arteries, or the arteries in the tongue. For an accurate reading of body temperature by oral thermometer, the mouth must remain sealed, with the tongue depressed for three to four minutes. This task may be difficult for young children, but the skill increases with age.
Oral thermometers can be either analog or digital. An analog glass-standard thermometer uses mercury or a non-mercury liquid to measure temperature. Digital thermometers use electronic heat sensors to record body temperature. They are usually considered safer than mercury-based thermometers, and can report a temperature quicker.
Pros:
- Easily accessible
- Less likely to be affected by environmental temperature
Con:
- Cannot be used with young children, or unconscious or uncooperative patients
Temporal Thermometry
Temporal thermometers use an infrared scanner placed in front of the forehead to measure the temperature of the temporal artery.
Pros:
- Records temperature quickly
- Relatively safe
- Easily tolerated
Con:
- More expensive
Tympanic Thermometry
Tympanic thermometers measure the thermal radiation emitted from the tympanic membrane (eardrum) and the ear canal. They are also referred to as infrared radiation emission detectors (IREDs). The blood supply of the tympanic membrane is similar to the temperature and location of the regulatory center (hypothalamus) of the body.
Pros:
- Records temperature quickly
- Generally comfortable for children
- Easily accessible
Cons:
- Earwax or a small, curved ear canal could interfere with accuracy
- Difficult to use in children less than 2 years of age because of narrow ear canal
Rectal Thermometry
Although rectal thermometry gets recognition as being the gold standard for temperature measurement in clinical practice, studies are finding limitations with this method.
Pros:
- Not affected by environmental temperature
- Supposed to be the closest to core temperature
Cons:
- Most parents are uncomfortable with this method
- Majority of children resent this method
- Measurements are affected by the presence of stool in the rectum
- Temperatures are slow to change in relation to changing core temperature
- Temperatures stay elevated well after the patient’s core temperature has begun to fall
Comparison of Temperatures (F°) by Thermometer Method
| Temporal | Oral | Rectal and Tympanic |
| 98.4 – 99.3 | 99.5 – 99.9 | 100.4 – 101 |
| 99.4 – 101.1 | 100 – 101.5 | 101.1 – 102.4 |
| 101.2 – 102 | 101.6 – 102.4 | 102.5 – 103.5 |
| 102.1 – 103.1 | 102.5 – 103.5 | 103.6 – 104.6 |
| 103.2 – 104 | 103.6 – 104.6 | 104.7 – 105.6 |
At Pocket Nurse, we take pride in providing our customers with the highest quality products, including thermometers, from the top manufacturers to ensure the most accurate and realistic experience is being practiced by the student.
Bailey Salvati was Sales Intern at Pocket Nurse in the summer of 2018. She graduated from the University of Pittsburgh with a degree in Communications, and she is now an Account Representative at Pocket Nurse. She can be reached at bsalvati@pocketnurse.com.
Sources:
Kaiser Permanente, Fever Temperatures: Accuracy and Comparison
Mayo Clinic, Thermometers: Understand the Options
US National Library of Medicine National Institutes of Health, Thermometry in Children
