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Temperature Measurement Sites
A thermometer measures body temperature. The common sites for measuring body temperature are the oral cavity, axillary region, temporal artery, and sk…
Body temperature can be measured in various regions of the body.
Surface body temperature is measured in the oral, axillary, and temporal areas, while core body temperature sites include the rectum and tympanic membrane.
Oral temperature is measured by placing a thermometer in the sublingual region. As this site is near the sublingual artery, it detects variations in core body temperature.
The axillary temperature is assessed by placing the thermometer in the middle of the axilla and adducting the arm toward the chest wall. This location is unreliable for determining body temperature as no major blood vessels are nearby.
The temperature at the forehead is measured by placing a thermometer over the temporal artery, which employs infrared technology to detect heat generated from the skin surface over the temporal artery.
The tympanic membrane temperature is measured by gently placing a probe in the ear canal and pressing it against the eardrum.
The rectal temperature is obtained by gently inserting a thermometer into the rectum. It is regarded as one of the most precise methods.
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Q1: What is the difference between surface and core body temperature measurement sites?
Surface body temperature is measured at oral, axillary, and temporal areas using skin or mucosal surfaces. Core body temperature reflects the temperature of internal organs and is measured at the rectum and tympanic membrane. Core sites provide more accurate readings of the body's true internal temperature, while surface sites are more accessible but less precise.
Q2: Why is oral temperature considered a reliable measurement site?
Oral temperature is measured by placing a thermometer in the sublingual region under the tongue. This site is near the sublingual artery, which detects variations in core body temperature accurately. The oral cavity offers reliable readings and can be used on intubated patients, though readings may be affected by recent hot or cold food consumption.
Q3: What are the advantages and limitations of tympanic membrane temperature measurement?
Tympanic membrane temperature uses infrared sensors to detect heat emitted by the eardrum and is considered core body temperature. Advantages include easy accessibility, high accuracy in critically ill patients, and quick measurement. Limitations include measurement variations, the need to remove hearing aids, and potential distortion from ear infections or environmental temperature devices.
Q4: Why is rectal temperature considered one of the most accurate measurement methods?
Rectal temperature is regarded as one of the most precise core temperature measurements because it directly reflects internal body temperature. It is a reliable alternative when oral temperature measurement is difficult. However, disadvantages include potential discomfort, bodily fluid exposure risk, and specific individual limitations that may restrict its use.
Q5: What makes temporal artery temperature measurement practical for clinical use?
Temporal artery temperature measurement uses infrared technology to detect heat from the skin surface over the temporal artery. It is quick, efficient, and requires no major patient repositioning or clothing removal. The method poses minimal risk of harm and does not require sensor covers, making it practical and non-invasive for rapid temperature assessment.
Q6: Why is axillary temperature measurement considered unreliable for determining body temperature?
Axillary temperature is assessed by placing a thermometer in the middle of the axilla with the arm adducted toward the chest wall. This location is unreliable because no major blood vessels are nearby to accurately reflect core body temperature. Axillary measurement also has prolonged measurement periods, lags during rapid temperature fluctuations, and underestimates core temperature.
Q7: What are the advantages of skin surface temperature measurement for newborns?
Skin surface temperature can be measured at the forehead, abdomen, and underarms using adhesive thermometers. Advantages include affordability, continuous reading capability, non-hazardous nature, and suitability for newborns. However, limitations include measurement lags during temperature fluctuations, adhesion problems from sweating, and reduced accuracy affected by environmental temperature.