Body Temperature-may be defined as “the degree of heat maintained by the body.

 

 Body Temperature :

·         Body temperature may be defined as “the degree of heat maintained by the body or it is the balance between the heat produced and the heat lost in the body”.

·         The regulation of the body temperature is  maintained by two mechanisms.

 

Thermo   genesis:

·         A chemical regulation by the production  of heat.

 

 

Thermolysis :

·         A  physical regulation by loss of heat

·         One of the most common observation made by the nurse in relations  to a patient’s condition  or progress is that of assessing Temperature, pulse and respiration –cardinal symptoms. These findings along with blood pressure are know as the “vital signs”.

·         A Patient’s vital signs are usually checked immediately on admission to a hospital or clinic, and they are usually repeated  at regular intervals ,as often as every 5 to 15 minutes during any acute stage and probably twice a day during the remainder of the hospital stay .

·         The heat regulating center is the hypothalamus situated in the brain. Heat is produced in the body   continuously. Unless it is lost from the body, no balance can be maintained.

 

 

1)      Heat is produced in the body by the following ways:

 

Oxidation of the Food:

 During the metabolism of protein, carbohydrate and fat, heat is produced as by product.

·         1 gm of carbohydrate gives 4 calories of heat .

·         1gm of protein gives 4 calories of heat .

·         1 gm of fat gives 9 calories of heat

  

  Specific Dynamic Action of Food :

  There is an increase in the production  of energy in the form of heat after taking food. This is not due to work in digestion or absorption but is due to the stimulating effect of food on basal metabolism. It is know as specific dynamic  action of food and it varies according to the different nutrients.

·         Specific dynamic action of fats is 4 percent.

·         Specific dynamic action carbohydrate is 5 to 6 percent

·         Specific dynamic action protein is30 percent.

·         Specific dynamic action of mixed diet is in 12 percent.

                           

        Exercise:

·         During exercise heat is produced faster than it is produced faster than it is eliminated from the body.

·         During exercise, the glycogen which is store in the body will be released and broken dowen into sugar with the release of energy.

·         The heavier the exercise, the greater will be the production of heat in the body.

·         During exercise ,the blood supply to the skin is increased and the individual feel hot .

     Strong Emotion

·         Excitement, anxiety, nervousness etc. stimulate the autonomic nervous system.

·         Which causes stimulation of the different organs in the body including the secreting glands.

·         Due to this increased activity, heat is produced in the body .

Hormonal effect:

·          Increase activity of the thyroid gland and the adrenal gland raise the body temperature.

·         Ovarian  hormone (progesterone ) produces a rise in the body temperature.

·         When these hormones are released into the blood, they stimulate the oxidation process and a large amount of the heat is produced in the body.

 

Change in the environmental and atmospheric conditions:

·         High room temperature increases the body temperature(by preventing the evaporation process).

·         Very high external temperature may upset the hat regulating mechanism and the temperature of the body will be increased to high level . e.g. sun stroke, heat stroke etc.

 

Disease conditions :

   Fever or pyrexia is caused by the bacterial invasion . it is the protective action of the body against the invading bacteria. The degree of temperature depends upon the severity of   infection.

N.B   :  There are certain condition in which the heat production is reduced in the body . they are:

·         Sleep : During sleep, the body is less active and heat production is less.

·         Fasting: In fasting and starvation, the fuel for the energy production is less.

·         Long term debilitating illness and lowered vitality of tissues.

·         Depression of the nervous system  e.g  in shock ,the  heat regulating mechanism is upset.

 

2)             Heat is lost from the Body by the following ways:

   The heat is lost from the body through different organs.

 

 

a)      Through the skin

·         The skin acts as one of the important organ in the heat regulation. It is controlled by hypothalamus.

·         When the body temperature is increased, the warm blood flow through the hypothalamus.

·         The hypothalamus which is very sensitive to heat variation in the blood ,send Impulses to the skin causing vasodilation .

·         Due to vasodilation more blood come to skin and evaporation but mostly by radiation.

·         Conduction Is the transfer of heat directly thought a substance from hot part to the cold part ,from one molecule to the other (by direct contact ).

·         Heat is transferred by conduction from the body to any substance in contact with the body such as air ,clothes, food stuffs, water etc. very little heat is lost by conduction.

·         Convection is the method of the transfer of heat by circulating air or liquid it depends upon the air  movement and the temperature of the atmosphere.

·         Radiation is the transfer of heat from the surface of one object to that on another which is not in contact with one anther.

·         Evaporation is the process y which substances in liquid state is changed into  vapor. Such a process requires heat.

·         Body loss a large amount of heat by way of evaporation of perspiration and sweat. Each gram of water takes up 580 calories of heat from its surroundings.

·         When the body temperature is increased ,the sweat gland become active and secrete sweet through which  the body heat is lost .   

 

b)     Through the lungs:

·         The temperature of the air which is taken to the lungs is that of the atmosphere an it is lower than that boy temperature.

·         On entering the respiratory tract ,it is warmed to that of the body temperature by absorbing heat from the lung tissue

·         As the individual breath out ,the warmed air is lost through the expired air.

·         Some of the body fluid is also vaporized and is lost through the expired air.

·         Approximately 300 ml. of water is also vaporized from the lungs daily . 

c)      Through the   kidneys  :

·         The kidney ecrete urine which is warmed by the heat take from the body . As the urine Is excreted ,the heat is also lost from the body

d)     Through the bowels:

·         the feces that are formed in  in the bowels absorbs heat from the body. So when the individual defecates, the heat is also lost from the body.

 

 

3)      Conservation of Body Heat:

·         The body heat is conserved by the type of clothing is worn. Cotton garments are good conduction of heat.

·         Therefore ,it helps to eliminate the excessive body heat in summer.

·         The woolen garments and blankets are used in winter season .

·         Wool Is a bad conductor of heat because of the air trapped in the interloking space of the material and there  by prevent the heat loss from the body.

·         Use of hot water  bottle and hot drinks helps to maintain the body temperature in a patient who is exposed to cold.

·         Rubbing the skin  surface raises the body temperature by temperature friction which changes the mechanical energy into thermal energy.

·         Cool drinks and cold sponges  reduce the temperature by evaporation of moisture from the skin.

 

   Normal variation in the body Temperature :

 In  a health individual , the body temperature may vary between 97 to 99 F(36.1 Ton37.2 C)

The following factor influence the variation in the body temperature :

·         Time of the Day : it is less in the morning and more in the evening .

·         Time of the month : menstruation cause a sudden fall in the temperature and rise slowly again after ovulation to a maximum just before the next menstrual  period.

·         Age of the person : Yong people have higher temperature than the old pepal 

 

Part of the body where the temperature is taken:

The temperature is highest when taken by rectum .

 It is 1   F   higher than the oral temperature

The temperature is lowest when taken by axilla. It is1   F   less than the oral temperature .

·         Emotions : The  temperature may vary in person with strong emotions.

·         Exercises :A heavy exercise will increase the body temperature  rest and sleep will reduce the body temperature

·         Fasting : The person who take no food may have a low temperature.

·         Environment factor : Hot and cold environment , hot and cold bath etc., may influence the body  temperature .

Therefore the body temperature recorded immediately  after taking a bath ,hot or cold drinks , smoking gum chewing of betel leaves is not reliable , so in such occasions wait for at least 15 minutes.