Body Temperature
General Objectives:-
Body TemperatureAt the end of this lecture the student should be able to demonstrate basic
knowledge related to body temperature.
Specific Objectives:-
Define Body Temperature.
Classify Body Temperature.
Mention Purpose of Measuring Body Temperature.
Discuss Factors affecting Body Temperature.
Enumerate Types of thermometer.
Alit Sites for Measuring Body Temperature.
List Alternations in Body Temperature.
Enumerate Signs of Fever.
Describe Nursing Care for Fever.
Describe Nursing Care for Hypothermia.
Outlines:-
Definition of Body Temperature. Kinds of Body Temperature.
Purpose of Measuring Body Temperature.
Factors affecting Body Temperature.
Types of thermometer.
Sites for Measuring Body Temperature.
Alternations of Body Temperature.
Signs of Fever.
Nursing Care for Fever and Hypothermia
Definition:-
It‘s the balance between the heat produced by body and the heat lostfrom the body. Normal body temperature using oral 37.0 Celsius or 98.
60 F.
Regulation of Body Temperature:
1. Body temperature is maintained within a fairly constant range by
the hypothalamus, which is located in the brain.
2. The hypothalamus functions as the body‘s thermostat. It normally
allows the body temperature to vary only about 1° to 2° Fahrenheit
(F) throughout the day.
3. Body temperature is maintained through a balance of the heat
produced in the body and the heat lost from the body.
4. A constant temperature range must be maintained for the body to
function properly.
5. When minor changes in the temperature of the body occur, the
hypothalamus senses this and makes adjustments as needed to
ensure that the body temperature stays within a normal and safe
range.
Heat Production:
1. Most of the heat produced in the body is through voluntary and
involuntary muscle contractions.
2. Voluntary muscle contractions involve the muscles over which a
person has control (e.g., the moving of legs or arms).
3. Involuntary muscle contractions involve the muscles over which a
person has no control; examples are physiologic processes such as
digestion, the beating of the heart, and shivering.
4. Body heat is also produced by cell metabolism. Heat is produced
when nutrients are broken down in the cells.
5. Fever and strong emotional states also can increase heat production
in the body.
Heat Loss Occurs Through the Following:
1. Conduction: Direct physical contact with an object.
2. Convection: When body heat warms surrounding air which rises
and is replaced by cooler air.
3. Radiation: Body heat warms surrounding objects without physical
contact.
4. Evaporation: Perspiration that is removed from the body surface
by change from a liquid to a vapor.
The purpose of Measuring Body Temperature:
1. To establish the patient‘s baseline body temperature.
2. To monitor an abnormally high or low body temperature.
Range of Body Temperature:
Temperature is measured on the Fahrenheit (F) or the Celsius (C)
scale. The average, normal, oral temperature for an adult is 98.6 degrees
Fahrenheit or 37.0 degrees Celsius (old term: centigrade).
Body Temperature Scales:
1. Body temperature is usually recorded using the Fahrenheit and
Celsius system of measurement.
2. You can convert Fahrenheit to Celsius or vice versa. To convert
Fahrenheit to Celsius, subtract 32 and multiply by 5/9. To convert
Celsius to Fahrenheit, multiply by 9/5 and add 32. See Table for a
conversion chart.
3. Body temperature may wary by 0.5ºF either way or still is within
normal limits.
Alterations in Body Temperature:
1. Feveror pyrexia: body temperature greater than 100.4°F (38°C).
2. When an individual has a fever, the heat of the body is producing is
greater than the heat of body is losing.
3. Hyperpyrexia: body temperature reading greater than 105.8°F
(41°C). Hyperpyrexia is a serious condition, and a temperature
greater than 109.4°F (43°C) is generally fatal.
4. Hypothermia: body temperature less than 97°F (36.1°C). The heat
of the body losing is greater than the heat it is producing.
5. A person usually cannot survive with a temperature less than
93.2°F (34°C).
Stages of Fever:
A fever can be divided into the following three stages:
1. The onset is when the temperature begins to increase. The increase
may be slow or sudden, the patient often experiences coldness and
chills, and the pulse and respiratory rate increase.
2. During the course of fever, the temperature rises and falls in one of
the following three fever patterns: continuous, intermittent, or
remittent. During this stage, the patient has an increased pulse and
respiratory rate and feels warm to the touch.
The patient also may experience one or more of the following:
1. Flushed appearance, increased thirst, loss of appetite, headache and
malaise.
2. Malaise refers to a vague sense of body discomfort, weakness, and
fatigue.
3. During the subsiding stage, the temperature returns to normal. It
can return to normal gradually or suddenly (known as a crisis).
4. As the body temperature is returning to normal, the patient usually
perspires and may become dehydrated.
Factors Influence Normal Body Temperature:
1. Metabolism differs. An increase in the emotional state of the
patient may increase the temperature.
2. Body temperature is usually lowest in the morning and highest in
the late afternoon or evening.
3. Normal temperature for infants and children is usually higher than
the normal adult temperature.
4. At birth, heat-regulating mechanisms are not fully developed, so a
marked fluctuation in body temperature may occur during the
infant's first year of life.
5. In some women, ovulation may be signaled by a slight drop in
body temperature 12 to 24 hours before a post-ovulation rise in
temperature of about 0.4º
F to 0.8º
F.
Assessment of Body Temperature:
Assessment Sites:
Five sites are available for measuring body temperature:
Mouth, axilla, rectum, ear, and forehead.
The locations in which temperatures are taken should have
an abundant blood supply so that the temperature of the
entire body is obtained, not the temperature of only a part of
the body.
1. Oral Temperature:
The oral method is a convenient and one of the most
common means for measuring body temperature. When the
medical assistant records a temperature, the physician
assumes it has been taken through the oral route, unless it is
otherwise noted.
A rich blood supply is found under the tongue in the area on
either side of the frenulum linguae.
The thermometer should be placed in this area to receive the
most accurate reading .The patient must keep the mouth
closed during the procedure to provide a closed space for the
thermometer.
2. Axillary Temperature:
Indications for taking an axillary temperature: The axillary site should be used for mouth-breathing
patients.
Patients with oral inflammation or who have oral surgery.
Oral and rectal routes are contraindicated.
3. Rectal Temperature:
The rectal temperature provides an extremely accuratemeasurement of body temperature because few factors can
alter the results.
The rectum is highly vascular provides the most closed
cavity.
Fig. (30): Rectal temperature
Indications for taking rectal temperature:
The rectal method is generally used for infants and young
children.
Unconscious patients and mouth-breathing patients.
When greater accuracy in body temperature is desired.
4. Aural Temperature:
The aural (ear) site is used with the tympanic membrane
thermometer.
The ear provides a closed cavity that is easily accessible.
Tympanic membrane thermometers provide instantaneous
results, are easy to use, and are comfortable for the patient.
They make it easier to measure the temperature of children
younger than 6 years, uncooperative patients, and patients
who are unable to have their temperatures taken orally.
5. Forehead Temperature
The temporal artery is a major artery of the head that runslaterally across the forehead and down the side of the neck.
In the area of the forehead, it is located approximately 2 mm
below the surface of the skin.
Because the temporal artery is located so close to the skin
surface and is easily accessible, the forehead provides an
ideal site for obtaining a body temperature measurement.
Fig. (32):Forehead temperature
Types of Thermometers:
The six types of thermometers available for measuring body
temperature are:
1. The clinical thermometer is a glass bulb containing mercury, with a
stem in which the mercury can rise:
The stem has lines representing the measuring scale. It must
read below normal range before the temperature is taken.
It should be rinsed in cold water to avoid distribution of the
mercury and breakage. If the thermometer is kept in a
chemical solution, dry it with a wipe in a twisting motion
starting at the bulb.
The clinical thermometer may be oral or rectal.
2. The oral thermometer has a long, slender bulb. It may also be used
for axillary measurement.
3. The rectal thermometer has a blunt, short, fat bulb. It should not be
stored with the oral thermometers.
4. Electronic. The electronic thermometer is portable and battery
operated. It registers the temperature in 10 seconds or less and
displays it digitally. It must be fully charged to give an accurate
reading, so be sure the thermometer's base is plugged into an
electrical outlet between uses. Separate oral and rectal probes are
supplied with each unit.
5. Disposable. The disposable is single-use and has a sensor at the
end of the shaft, which measures the temperature.
6. Patch. The thermometer patch is a strip, which contains liquid
crystals that change colors as the temperature changes. It is usually
placed on the forehead. The scale is adjusted to convert skin-
surface temperature to inner-body temperature. The calibration is
not as detailed as that of a glass thermometer.
Fig. (36): Thermometer patch
Common Terminology:
A pyrexia: A normal body temperature.
Body temperature: Represents the balance between the heat
produced by the body and the heat lost.
Circadian rhythm: Sleep cycle (body temperature is lower at
different times of the sleep cycle).
Core temperature: The temperature of the deep tissues and organs
within the cranial, thoracic and abdominal
cavities.
Evaporation: To lose heat through moisture, i.e. sweating.
Heat stroke: A potentially serious condition produced by
prolonged exposure to excessive temperatures,
which can lead to coma and death.
Homeostasis: Maintenance of a constant but dynamic
internal environment.