Monday, May 2, 2016

Taber's Medical Dictionary:Temperature

The degree of hotness or coldness of a substance.

TEMPERATURE REGULATION:Effects of changes in body temperature

TEMPERATURE REGULATION:Effects of changes in body temperature
absolute temperature
The temperature measured from absolute zero, which is −273.15°C.

Ambient temperature:
The surrounding temperature or that present in the place, site, or location indicated.

Axillary temperature:
The temperature obtained by placing a thermometer in the apex of the axilla with the arm pressed closely to the side of the body for the time recommended by the manufacturer of the thermometer. The temperature obtained by this method is usually 0.5° to 1.0°F (0.28° to 0.56°C) lower than temperature taken orally.

Video for Temperature: Axillary

Body temperature:
A marker of endocrine, metabolic, or muscle activity; the response of the body to heat or cold in the environment; or the presence of infection, inflammation, among other illnesses; it is one of the vital signs. Body temperature varies with the time of day and the site of measurement. Oral temperature is usually 97.5° to 99.5°F (36° to 38°C). Daily fluctuations in an individual may be 1° or 2°F. Body temperature may be measured by a placing a thermometer in the mouth and under the tongue, the rectum, under the arm, in the bladder, within the chambers of the heart, or in the external auditory canal of the ear. Rectal temperature is usually from 0.5° to 1.0°F (0.28° to 0.56°C) higher than by mouth; axillary temperature is about 0.5°F (0.28°C) lower than by mouth. Oral temperature measurement may be inaccurate if performed just after the patient has ingested cold or hot substances or has been breathing with an open mouth.
Body temperature is regulated by thermoregulatory centers in the hypothalamus that balance heat production and heat loss. Eighty-five percent of body heat is lost through the skin (radiation, conduction, sweating) and the remainder through the lungs and fecal and urinary excretions. Muscular work (including shivering) is a mechanism for raising body temperature. Elevation of temperature above normal is called fever (pyrexia), and subnormal temperature is hypothermia. Other factors that can influence body temperature are age (infants and children have a wider range of body temperature than adults, and elderly have lower body temperatures than others); menstruation cycle in women (the temperature rises in the ovulatory midcycle and remains high until menses); and exercise (temperature rises with moderate to vigorous muscular activity).

Core temperature:
The body's temperature in deep internal structures, such as the heart or bladder, as opposed to peripheral parts such as the mouth or axilla. In critical care it is often measured with a thermometer linked to a central venous catheter or pulmonary artery catheter.

Critical temperature:
The temperature above which distinct liquid and gas phases do not exist.

Inverse temperature:
A condition in which the body temperature is higher in the morning than in the evening.

Maximum temperature:
The temperature above which bacterial growth will not take place.

Mean temperature:
The average temperature for a stated period in a given locality.

Minimum temperature:
In bacteriology, the temperature below which bacterial growth will not take place.

Normal temperature:
The temperature of the body, taken orally, in a healthy individual, normally 97.5° to 99.5°F (36° to 38°C).

Optimum temperature:
The temperature at which a procedure is best carried out, such as the culture of a given organism or the action of an enzyme.

Oral temperature:
The temperature obtained by placing a thermometer under the patient's tongue with lips closed for 3 min or by electronic thermometer for the length of time noted on the readout or the manufacturer's direction. 

It should not be taken for at least 20 min after ingestion of hot or cold liquids. It is not advisable for infants, those who breathe through the mouth, the comatose or obtunded patients, or the critically ill.

Video for Temperature: Oral

Rectal temperature:
The temperature obtained by inserting a thermometer into the anal canal to a depth of at least 11/2 in (3.8 cm) and holding it in place for 3 to 5 min or, for electronic thermometers, according to the manufacturer's directions. This method should not be used following a rectal operation or if the rectum is diseased. A rectal temperature is more accurate than either oral or axillary temperatures. It averages about 1°F (0.56°C) higher than the oral temperature and approx. 1.5°F (0.84°C) higher than the axillary temperature.

Video for Temperature :Rectal

Room temperature:
The temperature between 65° and 80°F (18.3° and 26.7°C).

Subnormal temperature:
A body temperature below the normal range of 97.5° to 99.5°F (36° to 38°C).

Tympanic temperature:
The temperature obtained by placing an electronic probe in the ear canal. Such a reading measures the temperature in the capillary bed of the tympanic membrane and is generally reflective of the core temperature.

SEE: ear thermometry; SEE: thermometer, tympanic