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.

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.

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.

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.

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.

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.

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.