basal body temperature

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the degree of sensible heat or cold, expressed in terms of a specific scale. See Table of Temperature Equivalents in the Appendices. Body temperature is measured by a clinical thermometer and represents a balance between the heat produced by the body and the heat it loses. Though heat production and heat loss vary with circumstances, the body regulates them, keeping a remarkably constant temperature. An abnormal rise in body temperature is called fever.

Normal Body Temperature. Body temperature is usually measured by a thermometer placed in the mouth, the rectum, or the auditory canal (for tympanic membrane temperature). The normal oral temperature is 37° Celsius (98.6° Fahrenheit); rectally, it is 37.3° Celsius (99.2° Fahrenheit). The tympanic membrane temperature is a direct reflection of the body's core temperature. These values are based on a statistical average. Normal temperature varies somewhat from person to person and at different times in each person. It is usually slightly higher in the evening than in the morning and is also somewhat higher during and immediately after eating, exercise, or emotional excitement. Temperature in infants and young children tends to vary somewhat more than in adults.
Temperature Regulation. To maintain a constant temperature, the body must be able to respond to changes in the temperature of its surroundings. When the outside temperature drops, nerve endings near the skin surface sense the change and communicate it to the hypothalamus. Certain cells of the hypothalamus then signal for an increase in the body's heat production. This heat is conducted to the blood and distributed throughout the body. At the same time, the body acts to conserve its heat. The arterioles constrict so that less blood will flow near the body's surface. The skin becomes pale and cold. Sometimes it takes on a bluish color, the result of a color change in the blood, which occurs when the blood, flowing slowly, gives off more of its oxygen than usual. Another signal from the brain stimulates muscular activity, which releases heat. Shivering is a form of this activity—a muscular reflex that produces heat.

When the outside temperature goes up, the body's cooling system is ordered into action. Sweat is released from sweat glands beneath the skin, and as it evaporates, the skin is cooled. Heat is also eliminated by the evaporation of moisture in the lungs. This process is accelerated by panting.

An important regulator of body heat is the peripheral capillary system. The vessels of this system form a network just under the skin. When these vessels dilate, they allow more warm blood from the interior of the body to flow through them, where it is cooled by the surrounding air.
Abnormal Body Temperature. Abnormal temperatures occur when the body's temperature-regulating system is upset by disease or other physical disturbances. fever usually accompanies infection and other disease processes. In most cases when the oral temperature is 37.8°C (100°F) or over, fever is present. Temperatures of 40°C (104°F) or over are common in serious illnesses, although occasionally very high fever accompanies an illness that causes little concern. Temperatures as high as 41.7°C (107°F) or higher sometimes accompany diseases in critical stages. Subnormal temperatures, below 35.6°C (96°F) occur in cases of collapse; see also symptomatic hypothermia.
absolute temperature (T) that reckoned from absolute zero (−273.15°C), expressed on an absolute scale.
basal body temperature (BBT) the temperature of the body under conditions of absolute rest; it has a slight sustained rise during the luteal phase of the menstrual cycle and can be used as an indirect indicator of when ovulation has occurred.
body temperature the temperature of the body of a human or animal; see temperature.
core temperature the temperature of structures deep within the body, as opposed to peripheral temperature such as that of the skin.
critical temperature that below which a gas may be converted to a liquid by increased pressure.
normal temperature the body temperature usually registered by a healthy person, averaging 37°C (98.6°F).
risk for imbalanced body temperature a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as a state in which an individual is at risk of failure to maintain body temperature within the normal range.
subnormal temperature temperature below the normal. See also symptomatic hypothermia.

ba·sal bod·y tem·per·a·ture (BBT),

the temperature at rest, usually obtained on arising in the morning, without any influences that might increase it; can give indirect evidence of ovulation.

basal body temperature (BBT)

the temperature of the body under conditions of absolute rest, taken orally or rectally, after sleep, and before the patient does anything, including getting out of bed, smoking a cigarette, moving around, talking, eating, or drinking.

basal body temperature

The lowest normal body temperature that occurs during rest or sleep. Measurement of BBT is a popular method for determining whether ovulation has occurred, as the body temperature is 0.25–0.5ºCº (0.5–1.0ºF) higher post-ovulation.

basal body temperature

Reproduction medicine The lowest possible normal body temperature, which usually occurs in the morning before getting out of bed; measurement of BBT is a popular method for determining whether ovulation has occurred. See Anovulatory cycle.

ba·sal bod·y tem·per·a·ture

(bāsăl bodē tempĕr-ă-chŭr)
Temperature at rest, usually obtained on arising in the morning, without any influences that might increase it; can give indirect evidence of ovulation.

basal body temperature,

n temperature of the body determined in the morning, after sleeping and before any activity.
References in periodicals archive ?
relationship between basal body temperature nadir and
He knows from first-hand experience that the manual method of charting basal body temperature, which tells women when ovulation will occur, is imprecise, impractical and often frustrating.
In addition to the dramatic increase in pregnancy in the FertilityBlend group, improvement was also noted in the women's mid-luteal phase progesterone levels, basal body temperatures, and cycle length, as major indicators of the body's readiness to conceive.
More accurate than basal body temperature monitoring, these kits detect a surge in luteinizing hormone that appears 12-36 hours before ovulation and lasts for hours to a few days.
The FertilityBlend(TM) Optimization System contains a three month supply of FertilityBlend(TM) for Women, a clinically validated nutritional supplement that helps support fertility health by enhancing hormonal and menstrual cycle balance; a three month supply of FertilityBlend(TM) for Men, a scientifically validated nutritional blend that enhances sperm count, motility, and quality; instructions on how to track basal body temperature (BBT thermometer and charts included) to help determine exact ovulation date; a kit with five ovulation predictor tests to optimize conception timing; and a set of three home pregnancy tests to confirm pregnancy.
If in three months, the TSH decreases (even if it was in the high normal range to start with), the T4 is normal, and the patient notices an upsurge in energy and an increase in basal body temperature, it is reasonable to diagnose iodine deficiency.
Pheromone advises that in their recent US trial, the PSC Fertility Monitor detected more days of the conception window (the days when sexual intercourse can lead to a pregnancy) than the LH test strip product or the basal body temperature method.