Fever or pyrexia is defined as a rise in the body temperature above 37.2 degree celcius.

 The cause of fever is infections, diseases of the nervous system, certain malignant neoplasms, blood diseases such as leukaemia, embolism and thrombosis, heat stroke from exposure to hot environments, dehydration, surgical trauma and crushing injuries, skin abnormalities that interfere with heat loss, allergic reactions to foreign proteins and pyrogens etc.

In fever, all the systems of the body are affected. It may vary with the nature of the disease.

Respiratory system: shallow and rapid breathing.

Circulatory system:
increased pulse rate and palpitation

Alimentary system: dry mouth, coated tongue, loss of appetite, indigestion, nausea, vomiting, constipation or diarrhea

Urinary system: diminished urinary output, burning micturition, high colored urine

Nervous system: headache, restlessness, irritability, insomnia, convulsions, delirium

Musculo-skeletal system: malaise, fatigue, body pain, join pain

Integumentary system: heavy sweating, hot flushes, goose flush, shivering or rigors

Fever is not a disease but it is a sign. Fever is a protective function of the body, because the rise in temperature prevents the growth of organisms causing the disease. Fever if not too high, hastens the destruction of bacteria by increasing phagocytosis and by producing immune bodies. A temperature of 100 to 105 degree F for several hours will destroy the organisms of syphilis and gonorrhea.

The range in the body temperature within which the cells can function efficiently in between 34 and 41 degree celcius. The central nervous system is extremely sensitive to the temperature variations. Irreversible changes may occur in the nervous system if the body temperature goes above 41 or below 34 degree celcius.

Types of Fever

Terms used to define the Types and Phases of Fever

Onset or invasion: onset or invasion of fever is the period when the body temperature is rising and it may be a sudden or gradual process.

Fastigium or stadium: fastigium or stadium of fever is the period when the body temperature has reached its maximum and remains fairly constant at a high level.

Defervescence or decline: defervescence or decline of the fever is period when the elevated temperature is returning to normal. The fever may subside suddenly (decline by crisis) or gradually (decline by lysis)

Crisis: crisis is a problem return to normal temperature from a very high temperature within a few hours or days.

True crisis: the temperature falls suddenly within few hours and touches normal, accompanied by a marked improvement in the client’s condition.

False crisis: a sudden fall in temperature not accompanied by an improvement in the general condition is called false crisis. It may be a danger signal and not a sign of improvement.

Lysis: the temperature falls in a zig-zag manner for 2 or 3 days or a week before reaching normal, during which time the other symptoms also gradually disapper.

Constant fever or continuous fever:
constant fever or continuous fever is one in which the temperature varies not more than two degrees between morning and evening and it does not reach normal for a period of days or weeks.

Remittent fever:
remittent fever is a fever characterized by variations of more than two degrees between morning and evening but does not reach normal.

Intermittent or quotidian fever: the temperature rises from normal or subnormal to high fever and back at regular intervals. The interval may vary from few hours to 3 days. Usually the temperature is higher in the evening than in the morning.

Inverse fever: in this type the highest range of temperature is recorded in the morning hours and the lowest in the evening which contrary to that found in the normal course of fever.

Hectic or swinging fever: when the difference between the high and low points is very great, the fever is called hectic or swinging fever.

Relapsing fever: relapsing fever is one in which there are brief febrile periods followed by one or more days of normal temperature.

Irregular fever: when the fever is entirely irregular in its course, it cannot be classified under any one of the fevers described above and it is called irregular fever.

Rigor: rigor is a sudden severe attack of shivering in which the body temperature rises rapidly to a stage of hyperpyrexia as seen in malaria

Low pyrexia: in low pyrexia the fever does not rise between 37.8 and 37.8 degree celcius.

Moderate pyrexia:
the body temperature remains between 37.8 and 40.6 degree celcius.

High pyrexia:
the temperature remains between 39.4 and 40.6 degree celcius.

Subnormal temperature:
when the body temperature falls below normal, it is called subnormal temperature. The temperature may vary between 35 and 36.7 degree celcius.

when the body temperature is raised to 105 F or above it is called hypethermia.

if the temperature falls below 95 F or 35 F, the condition is called hypothermia.

Fever (Pyrexia) and Rigor – Definition, Types Nursing Care and Observation.

fever (pyrexia) - nursing care

Nursing Care in Fever

Regulation of the Body Temperature

Care of the clients in fevers focuses on reducing the elevated body temperature. When a client’s temperature is moderately elevated, various methods of reducing the temperature may be started. The room should be maintained at a comfortable temperature. The room should be well ventilated. The blankets and excess clothing should be removed but prevent the client from getting draughts.

The various methods used for cooling the body are:

Exposure to cool by an electric fan

Administration of cool drinks

Application of cold compress and ice bags

Cold sponging and cold packs

Cold bath

Ice cold lavages and enemas

Use of hypothermic blankets or mattresses

When surface cooling is used, treatment is directed at not only cooling the body but also for preventing shivering. Shivering must be prevented because it increases metabolic activity, produces heat, increases the oxygen usage markedly, increases circulation, and may cause hyperventilation and respiratory alkalosis. It takes longer time to reduce body temperature in a shivering client.

Meeting the Nutritional Need

The cellular metabolism is greatly increased during fever. The oxygen consumption in the body tissues increases approximately 13 % for each centigrade degree of rise in temperature or 7 % for each Fahrenheit degree. Therefore, a high calorie diet is indicated in fevers. Since, the digestive process is slowed down, the diet should be easily digestible and palatable. Most of the clients prefer fluid diet.

Unless it is contraindicated, the fluid intake is increased to 3000 ml in 24 hours to prevent dehydration and to eliminate the waste products. The clients with fever, lose a large amount of fluid through sweating. If nausea vomiting, or diarrhea is present, intravenous fluids may be given with the permission of the physician. If there is burning micturition, encourage the client to take plenty of fluids. An intake and output chart is maintained in all clients with fever.

The client who tolerates solid diet should be given small and frequent feeds. Never force a client to take any food he dislikes. In order to stimulate appetite, the diet should be served attractively. Due to the coated tongue, the client may not enjoy the taste of the food, so the food should be made palatable.

A diet, which is soft and containing plenty of fluids and fruits will help to evacuate the bowels regularly.

Providing Rest and Sleep

All clients having fever should be asked to take complete bed rest. To ensure rest and sleep, provide a unit, which is calm, quiet, without bright lights and glares. Help the client to change the position regularly. The clothing should be light, loose, smooth and non-irritating. Cotton garments are helpful, since they absorb the sweat and help in the evaporation.

Maintenance of Personal Hygiene

Care of the mouth is very essential for clients having fever for many days. There may be cracked lips and coated tongue. If the oral hygiene is not maintained, many complications may arise, e.g., parotitis, sords and crusts, herpes etc. mouth care is given 4 hourly or even more frequently for those clients having fevers for many days. Apply any one of the emollients to the dry lips to prevent cracking.

Care of the skin and pressure points are essential to prevent bedsores. Sponge bath is given daily to keep the client clean. If profuse sweating is present, frequent sponging is essential. A 4 hourly back care may be given with special attention to the pressure points. If the temperature is remaining high, the cold sponging may be given to bring down the temperature.

Safety Factors

Never leave a client with high fever alone. Rigors and convulsions may occur at any time and the nurse should keep all the articles ready to act quickly on such occasions. If the client has a fever over 103 F for a long time it may lead to delirium and convulsions. If the temperature is remaining high for a long time irreversible changes may occur in the brain cells. If the temperature is not coming down with cold applications, antipyretic drugs e.g., paracetamol may be given with the advice of the doctor.

Surface cooling should be done gradually. Sudden cooling can lead to serious side effects such as cardiac arrhythmias. When the temperature is brought down to the desired level, the client should be protected with warm blankets to prevent them going to hypothermia.

If any type of cold applications is used, the nurses should inspect the skin for discoloration or lesions and apply a cream or oil to the affected area.


Observation of the Client

Clients with fever need constant intelligent observation by the nurses. The vital signs are to be checked frequently to know the progress or regression of the disease. Any worsening of the client’s condition should be noted and reported immediately.

When any type of cold applications is applied, the temperature should be taken by the rectal method to get an accurate body temperature. Measure and evaluate the urinary output periodically.

Care in Rigor

Rigor is characterized by three stages:

First stage or cold stage:

The client shivers uncontrollably. The skin is cold, face is pinched and pale, the pulse is feeble and rapid. The temperature rises rapidly to 39.4 degree celcius or above. In this stage, cover the client with blankets and apply warmth with hot water bags. Give warm drinks. Protect the client from falling.

Second Stage or Hot stage:

The skin feels hot and dry and client feels very thirsty. The shivering stops. The clients may be restless. The temperature may continue to rise.

During the second stage, remove all the blankets and hot appliances. Cover him only with a thin blanket. Give him cool drinks. Cold compresses are applied to the head to relieve congestion and headache. The temperature is carefully recorded every 10 to 15 minutes. Watch pulse and respirations carefully. If the temperature goes very high (40.5 degree celcius) cold sponging may be started. Watch for the early signs of sweating.

Third Stage or Stage of Sweating:

The clients sweat profusely. The temperature falls. The pulse improves. Acute discomforts are diminished. The client may go into a state of shock and collapse if not cared properly.

During the third stage, change the clothes that are wet with sweat or with cold applications. Give a quick sponge and dry the client. Put on clean dry clothes and cover the client with a light cotton blanket. Sweet drinks may be given to treat fatigue. Make him comfortable. Let the client sleep. Continuous watching is necessary. Take T.P.R. every 15 minutes, without disturbing the client. When the temperature comes down and the pulse is not improved, it should be considered as a false crisis and the client’s condition may deteriorate unless carefully watched.