Temperature

Temperature-

" Body temperature may be defined as the degree of heat maintained by the body."

"Temperature is the degree of sensible heat or cold, expressed in terms of a specific scale."

"It is the balance between the heat production and heat loss from the human body. Body heat is measured in degrees."
Temperature is a physical property of matter that quantitatively expresses hot and cold. It is the manifestation of thermal energy, present in all matter, which is the source of the occurrence of heat, a flow of energy, when a body is in contact with another that is colder.

Body temperature can be measured by placing the clinical thermometer in different parts of the body such as-

Mouth (oral temperature)
Axilla (axillary temperature)
Rectum (rectal temperature)

Sites

The common sites for taking body temperature are-

Mouth
Axillary
Rectum
Tympanic membrane
Vagina
Groin

Normal body Temperature- Normal body temperature in human is 37°C (98.6°F), when measured by placing the clinical thermometer in the mouth (oral temperature). It varies between 35.8°C and 37.3°C (96.4°F and 99.1°F).

Temperature at Different parts of the Body-

Axillary temperature is 0.3°C to 0.6°C (0.5°F to 1°F) lower than the oral temperature.-97.61°F (36.4°C)
The rectal temperature is 0.3°C to 0.6°C (0.5°F to 1°F) higher than oral temperature.-99.6°F (37.5°C)

Purposes of Measuring Body Temperature

To have baseline data about patient.
To assess the patient’s condition.
To determine the effectiveness of treatment.

Types of Temperature

Core Temperature
Surface Temperature

Core Temperature-Core temperature is the average temperature of structures present in deeper part of the body. The core temperature is always more than oral or rectal temperature. It is about 37.8°C (100°F)

Surface Temperature- It is temperature of skin, subcutaneous tissues and fat, It can according to environmental temperature.

Variation of Body Temperature-

A.Physiological Variations

Age

In infants, the body temperature varies in accordance to environmental temperature for the first few days after birth. It is because the temperature regulating system does not function properly during infancy. In children, the temperature is slightly (0.5°C) more than in adults because of more physical activities. In old age, since the heat production is less, the body temperature decreases slightly.

Sex

In females, the body temperature is less because of low basal metabolic rate, when compared to that of males. During menstrual phase it decreases slightly.

Sleep

During sleep, the body temperature decreases by 0.5°C.

Emotion

During emotional conditions, the body temperature increases.

Menstrual cycle(Hormonal Level)

In females, immediately after ovulation, the temperature rises (0.5°C to 1°C) sharply. It decreases (0.5°C) during menstrual phase.

Diurnal variation

In early morning, the temperature is 1°C less. In the afternoon, it reaches the maximum (about 1°C more than normal).

After meals

The body temperature rises slightly (0.5°C) after meals.

Exercise

During exercise, the temperature raises due to production of heat in muscles.

B. Pathological Variations-

Abnormal increase in body temperature is called hyperthermia or fever and decreased body temperature is called hypothermia.

Heat Gain (Production)-

Metabolic Activities

Major portion of heat produced in the body is due to the metabolism of foodstuffs. It is called heat of metabolism. Heat production is more during metabolism of fat. About 9 calories of heat is produced during metabolism of fats, when 1 L of oxygen is utilized. For the same amount of oxygen, carbohydrate metabolism produces 4.7 calories of heat. Protein metabolism produces 4.5 calories/L. Liver is the organ where maximum heat is produced due to metabolic activities.

Role of Hormones

Thyroxine and adrenaline increase the heat production by accelerating the metabolic activities.

Radiation of Heat from the Environment

Body gains heat by radiation. It occurs when the environmental temperature is higher than the body temperature.

Muscular Activity

Heat is produced in the muscle both at rest and during activities. During rest, heat is produced by muscle tone. Heat produced during muscular activity is called heat of activity. About 80% of heat of activity is produced by skeletal muscles.

Shivering

Shivering refers to shaking of the body caused by rapid involuntary contraction or twitching of the muscles as during exposure to cold. Shivering is a compensatory physiological mechanism in the body, during which enormous heat is produced.

Brown Fat Tissue

Brown adipose tissue is one of the two types of adipose tissues, the other being white adipose tissue.

Heat Loos from the Body-

Maximum heat is lost from the body through skin and small amount of heat is lost through respiratory system, kidney and GI tract.

1. Conduction

Three percent of heat is lost from the surface of the body to other objects such as chair or bed, by means of conduction.

2. Convection

Fifteen percent of heat is lost from body to the air by convection. First the heat is conducted to the air surrounding the body and then carried away by air currents, i.e. convection.

3 Evaporation

Insensible Perspiration When water evaporates, heat is lost. Twenty two percent of heat is lost through evaporation of water. Normally, a small quantity of water is continuously evaporated from skin and lungs. We are not aware of it. So it is called the insensible perspiration or insensible water loss.

4 . Radiation

Sixty percent of heat is lost by means of radiation, i.e. transfer of heat by infrared electromagnetic radiation from body to other objects through the surrounding air.

5. Panting

Panting is the rapid shallow breathing, associated with dribbling of more saliva. In some animals like dogs which do not have sweat glands, heat is lost by evaporation of water from lungs and saliva by means of panting.

SCIENTIFIC PRINCIPLES OF TEMPERATURE

Anatomy and Physiology

The heat regulating center is hypothalamus and it is situated in the brain. The regulation of body temperature is maintained by two mechanisms.

Thermogenesis-a chemical regulation by production of heat
Thermolysis-a physical regulation by loss of heat

Heat is produced in the body by oxidation of food. I g CHO gives 4 calories of heat. I g protein gives 4 calories of heat and 1 g fat gives 9 calories of heat.
More oxidation takes place in muscles and glands.
Heat is also produced by specific dynamics action of food, exercise, strong motions, hormonal effect. change in the environment and atmospheric conditions.
The sweat glands keep the skin moist so that cooling results from evaporation.
In fever, skin is pale due to constriction of the peripheral blood vessels.
When the body temperature is abnormally high, a cold bath or a cold environment may produce comfort.

Microbiology

Thermometers must be clean when they are used. Before and after, it should be disinfected with spirit
Before taking the temperature, wipe the thermometer from bulb to the stem to keep the bulb clean. After taking temperature, wipe it from the stem to the bulb to avoid contamination of the finger of nurse with saliva or feces.
During the cleansing process, wipe it from the tip to avoid contamination.

Physics and Chemistry

Heat is lost from the skin by radiation, convection, conduction and vaporization.
Blankets are applied to raise the body temperature because blankets are full of air spaces and serve as Insulation and keep the body hot.
Rubbing the body surface increases heat in the skin by friction.
Mercury is used in the clinical thermometer. It is liquid metal with silvery appearance.
Heat is produced by the body is a by-product of metabolism which is the chemical reaction in all body cell.

Psychology

Explain the procedure to the patient to get the co-operation.
Explain the patient that mouth should be closed while the thermometer is put in the mouth.
Do not leave the thermometer in the mouth for longer time because the patient may fell uncomfortable.
Screen the patient and cover him while taking temperature by rectum.
Do not tell the patient his temperature as patient is unduly alarmed.
Keep the sphygmomanometer and stethoscope in the duty room/cupboard
Report any deviation from normal.

General Instructions For Taking Temperature

Wash hands before and after procedure.
The thermometer are disinfected in a proper disinfectant.
The disinfectant solution should be changed daily.
Provide comfortable position to the client.
Before procedure, determine the route of taking temperature by mouth, by axilla or by rectal.
Before procedure, collect all the articles near bedside of the patients.
Select proper sites for temperature.
Before taking the oral temperature check the client had any hot or cold drinks.
Before and after procedure clean the thermometer.
Do not washing the thermometer.
Instruct the client not biting on the thermometer.
Read the thermometer at the eye level and proper light.
Maintain calm and quite environment while doing procedure.
Never leave the client alone.
Never tell the client his temperature.
Store the thermometer properly.
Never touch the bulb of the thermometer.
Do not use the oral thermometer for taking rectal temperature.
Record the temperature immediately and accurately.