Fever is a sign that is wrongly interpreted by many individuals. This is something commonly not corrected.
Usually temperature checks are routinely done in hospitals or medical centre when we go and see a doctors. Now having temperature taken is part of daily requirement in life.
To understand what fever is, you will need to understand what is the normal body temperature,the difference in High temperature as in fever and what is the mechanism of fever in the body.
Fever is elevation in the core body temperature to above the daily range for an individual. There is no universal threshold for fever, as normal body temperature varies by individual, time of day and how it is measured.
Based on studies documenting variation temperature more than 37.2 C (oral) in the morning is normal body temperature or afternoon temperature 37.7 C ( 99.9 F) could be considered fever. The general threshold is more than 37.8C (100.0 F) or more than 38C (100.4F).
It is established that the baseline temperature in older adults is lower than in younger adults and thus temperature lower than the threshold may still reflect fever (potentially severe infection) in older adult patients.
Which mean older adults can have a severe illness and not have high temperature as expected. To begin with normal temperature is between 35.3 to 37.7 C (99.5 F to 99.9F) which is measured orally. Any temperature above 38 C or ( 100.4 F ) is called fever and this will vary depending on how the temperature was taken oral (mouth), armpit, ear tympanic closed to the core temperature are accurate, forehead or rectal ( 0.6 higher than oral ).
Mechanism of fever
Fever is be controlled at the level of the hypothalamus in the brain .We can call this a thermostat device, which set the core temperature with a normal range. At this range the body function at its optimum functional level or maintain at what is called homeostasis. The thermostat device in the hypothalamus can be reset to a higher or lower temperature depending of feedback and triggering factors coming from the body.
So for example if the thermostat is set to 36 C the body tries to keep core body temperature at 36 C. If the temperature were to drop let say from exposure to cold.
The thermostat in the hypothalamus activate heat conserving mechanism i.e. activate muscle activities and movement e.g. hand rubbing on skin to keep warm, hair on skin pore closed up resulting in hair standing on skin, something we are all familiar with. In doing so the pores on your skin closed up to retain heat in the body and if that is not enough then we start shivering, something that happen automatically . All of this activities just to maintain body temperature at 36C.
If this process is very successful and the temperature is rise above 36 C the body reverse it approach and activate heat loosing mechanism. In this case muscle activities cease, the skin pores open and you start sweating,the shivering stops.
This continues until temperature is back to normal. This is the principle on how temperature is regulated in the body. Fever is one of the triggering factor that can reset the thermostat device in the Hypothalamus to a higher temperature. The idea of resetting thermostat at higher temperature is to destroy any invading element or pathogens which include bacteria or viruses. Therefore fever is one of the body nonspecific defense against invading pathogen.
It’s non-specific because increasing body temperature generally target all pathogens. This can be related to boiling water to kill organism to make the water safe to drink.
During this time the chills and rigors is experience indicating early infection with not sweating. Historically this was a time lots of blankets were used to cover patient at home.
The treatment speed up the body heating process to achieve the reset Higher temperature regulated by the thermostat at the hypothalamus. The end result in sweating indicating that the target temperature is achieve and the triggering factor removed. Once again the thermostat reset to the original temperature.
This activate heat relieving mechanism like opening of skin pores and sweating gradually cooling the body back to the normal range. The historic use of blanket to increase body temperature rapidly is not suitable for all patient especially children.
Sudden increase in body temperature in certain very young children s can result is seizures called febrile convulsion. In this case antipyretic is needed and a common medication used is Panadol. Common causes of fever in adults?
Coronavirus 2019 (COVID);
A cold and fl u; Airway infection such as bronchitis; and
A stomach bug. In children the common cause of fever up to 55 to 60 per cent is bacterial or viral infection. This is confirm by doctors during medical examination. The majority of these patients have acute otitis media (ear infection) and throat infection, although unimmunised or incompletely immunised children with acute otitis media and a temperature
39°C (102.2°F) are still at risk infection in blood. Recognisable viral illness (e.g., croup, bronchiolitis, infl uenza, varicella, or rosella) accounts for up to 6 per cent of young children presenting with fever. Fever and cough or sore throat are common symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children. Nasal congestion, vomiting, and diarrhea have also been noted.
When should I see a doctor or nurse?
If you leave in an area where people have COVID-19. They will ask question about your symptoms and whether you might be are risk and they also can tell you if you should get tested as well. Call or go see you doctor or nurses if you have fever and the following:
pregnant;
recently get out of hospital or had surgical or medical procedure;
get infection often;
on chemotherapy;
take medication to suppress the body infection fighting system called immune system example are steroid medication to prevent rejection after organ transplant;
fever last several days and keep coming back; and
if you have serious health condition such as diabetes, heart disease, cancer lupus or sickle cell anemia. Also if you have fever plus:
rash;
trouble breathing;
severe head ache and neck pain;
seizure and confusion;
severe pain in belly back or side; and
any symptoms that is unusual and worries you.
Will I need tests?
Maybe your doctor or nurse on examine you and talk about your symptoms and you might have the following test.
A swab from inside your nose;
Blood test;
Urine test;
Chest X ray or CT scan ( this imaging test create picture of the inside of your body; and
You will be informed of other test which you might need.
What can I do on my own to feel better?
Stay Home rest and drink plenty of fluids and take acetaminophen to relive fever.
How is fever treated?
That depend on the cause. Many people don’t need treatment. If you do, treatment can include: Antibiotic to fight bacterial infection and not infection caused by viruses.
Medicine such as acetaminophen for fever. The medication can bring down fever but they are not always necessary. These are some understanding on fever. How it works and how you can managed this and more important when you should be seen by a doctor to seek treatment. Hopefully this give better insight about what fever is about and how the body regulate temperature as a broad nonspecific defense mechanism against pathogens.
DR JOHN ALFRED is the practice manager and general practitioner at Oceania Hospitals Pte Ltd. The views expressed are the author’s and do not reflect the views of this newspaper).
