What Is a Fever?

For many people, when a fever hits, they start to worry because we’ve been conditioned to think of fever the way we think about a house fire: Put out the fire before it gets out of control and kills someone! And the first response, typically, is to take medication – a fever reducer, such as ibuprofen or acetaminophen. This kind of medication can bring the temperature down and alleviate other symptoms like muscle aches and headache. But is taking a fever reducer the best way to handle a fever? Is a fever like a fire burning out of control?

 

 

Not at all. Let’s find out why. 

 

 

When the body detects a germ intruder, it marshalls its defenders, sending white blood cells to the infected area. The white blood cells release chemical messengers, signaling the body to raise the temperature because a higher temperature enables the white blood cells to do their work more effectively. Not only are they able to work more effectively, fever increases the speed at which white blood cells move to the site of crisis.  When your body turns up the heat, its fighting troops, the white blood cells, move quickly to attack and destroy enemy invaders. When there’s an enemy invasion, you want energetic troops to be dispatched with speed. You don’t want ineffective soldiers who move sluggishly “defending” your borders.

 

 

For this reason, Dr. Agatha Thrash says fever “is not an enemy, but a friend.” Fever is an immune response that supports the body in its work of combating illness. Therefore, says Dr. Thrash, “The forcible reduction of temperature in fevers by ice water applications is usually not wise. The body begins to work against you, and the immune system is weakened.” Research shows that the results of fever suppression are longer bouts of illness and worsened disease conditions. For those who may be fearful of fever, Dr. Thrash says, “Most fevers, especially in small children, represent only a mild, self-limited illness” and fevers can usually “be allowed to run their course with no treatment.” 

 

 

Normal Body Temperature

The human body maintains a normal temperature around 98.6° F (37° C) but temperatures between 97-99° F (36.1-37.2° C) for adults are in the normal range. Individuals have their own range which differs from one person to another. An average normal temperature for one person could be a whole degree higher or lower than for another. Women tend to have higher temperatures than men, while babies are hotter still. The elderly are often cooler. In addition, the body’s temperature tends to fluctuate during the day, with lower temperatures in the morning and higher in the evening being the norm. All this is regulated by a small gland in the brain called the hypothalamus.

 

In the case of an infection, the hypothalamus may set a higher temperature for the body to aid the immune system in fighting pathogens. The first sign you may notice that your internal thermostat has been turned up is chills. Because a new higher temperature has been set, you may begin to shiver as your body works to generate more heat. 

 

For every degree of temperature rise in your body, the white blood cells –the cells that fight infection and bacteria – move faster and their effectiveness increases. A fever is created by your immune system to speed up your body’s response to disease and infection. 

 

As your immune system makes headway against infection, the hypothalamus will reset your body’s temperature back to normal. This is when you’ll feel hot. In an attempt to bring your temperature back to its normal set-point, you’ll sweat, as sweating is a cooling mechanism. Support your body during this process by keeping well hydrated. Sip water frequently. Add lemon juice or a pinch of Celtic salt to provide electrolytes.

 

Developing a fever in response to an infection is different than when the body overheats in the case of heatstroke. In heatstroke the body’s internal temperature rises above the temperature set by the hypothalamus. Heatstroke is a medical emergency which can damage organs such as the brain, heart, kidneys, and muscles.

 

Fever, on the other hand, can be thought of as a controlled burn which very rarely results in lasting damage. Instead, a rise in the body’s internal temperature enhances immune system function, increasing the production and activity of immune cells. At the same time, heat reduces the spread of infection by destroying or inhibiting pathogens such as disease-causing bacteria or viruses. In addition, developing a fever early in an illness may prevent the development of more severe symptoms later on.¹ 

 

 

Should I use a Fever Reducer?

Some mistake fever for the illness itself and feel that if they can get rid of the fever, they’ll get better again. Do fever reducers like ibuprofen, acetaminophen, or aspirin “cure” a fever? No. These drugs suppress the body’s immune response. While it’s true that antipyretics, or fever reducers, can reduce the symptoms of illness and help you feel better quickly, their use comes at a cost because they interfere with the body’s ability to deal with the infectious agent. Because of this, the use of fever reducers can prolong illness or worse.

 

 

Studies in patients with chickenpox and malaria found that those who were given acetaminophen experienced delayed recovery. In contrast, in studies of patients with severe infection, “fever was associated with lower mortality, and those with the highest body temperatures had the best survival.”² 

 

Despite the fact that fevers have benefits, the usual treatment recommended by medical practitioners is fever-reducing drugs. Forcing the body back to a normal temperature may remove the discomfort of being sick. But a fever is not caused by pathogens. It is a sign that your body is responding as it should to germs. And most of the time, sweating out a fever is far better than bringing your temperature down with fever reducers.

 

But isn’t fever dangerous? Don’t fevers cause seizures?

 

 

Febrile Seizure

Febrile seizures, or convulsions that are triggered by a fever, may cause a child to lose consciousness, the arms and legs may shake or become rigid, and the eyes may roll. While these symptoms may be terrifying for a parent to watch,  febrile seizures tend to stop within a few minutes and are harmless, with no lasting effects. Dr. Thrash notes, “The major objective with convulsions in children from fevers is that of comforting the distraught parents.”³ Convulsions associated with fever have more to do with how quickly the temperature rises than how high the temperature goes.⁴

 

Febrile seizures are fairly common in young children, with an incidence rate of 2-5% in children between 6 months and 5 years of age.⁵ There are two kinds of seizures: simple and complex. Most febrile seizures are classified as “simple,” that is a single, generalized seizure that resolves within 15 minutes. Complex febrile seizures include those that: the child does not fully recover from within an hour, last more than 15 minutes, recur within 24 hours, or present with symptoms focused in one part of the body only.⁶

 

Studies on febrile seizures found that most children recover within 24 hours and have minimal or no neurological aftereffects.⁷ There is some concern that complex febrile seizures can increase the risk of epilepsy, but this fear appears to be exaggerated.⁸ A review of studies concluded that children who experience simple febrile seizures are not likely to be impacted over the long-term, noting that “serious outcomes are rare; intellectual or behavioural impact are not reported, and there is no increase in mortality compared to the general population 2 years after the seizure."⁹

 

Can using fever-reducing medications prevent febrile seizures? InformedHealth.org, an evidence-based health education service, states that “research suggests that fever-reducing medication can't prevent febrile seizures.”¹⁰ In addition, though seizures typically occur at fevers above 101° F (38.3°  C), they can sometimes occur even at 100.4° F (38° C).

 

 

Effects of High Fever on the Brain

Can a high fever cause brain damage? Temperatures of 41.5°  C or more are dangerous to the central nervous system. But such high temperatures occur very rarely and only happen when the air temperature is very high. According to Seattle Children’s Hospital, “Normal fevers between 100° and 104° F (37.8° - 40° C) are good for sick children.”¹¹ Nevertheless, monitoring the sick patient especially when their fever starts to reach 40° C is important to be able to take measures to prevent it from getting into dangerous levels. 

 

When adverse outcomes occur in children with fever, other factors are responsible. In a review of medical studies involving children and fever, researchers noted that adverse events following fever are “related to the underlying condition rather than to the rise in temperature.”¹²

 

 

Overuse of Fever Reducers

Of more concern is the overuse of antipyretics, fever reducing drugs, such as aspirin, ibuprofen, acetaminophen, and others. Researchers warn, “The most serious and common adverse events associated with fever are related to antipyretic drugs.”¹³  And yet, “antipyretics are the most common medications administered to children.”¹⁴ Serious drug effects include liver and kidney injury and gastrointestinal bleeding. Dosing errors and frequency of administration are most often the cause of drug-related injuries in fever treatment in children. 

 

Fever reducers and vaccination

What about taking a fever reducer like ibuprofen or acetaminophen after getting a vaccine? Many health professionals advise patients to take antipyretics to treat the pain and fever caused by vaccination. Is this warranted? As has already been shown, antipyretics interfere with the body’s normal immune response. Researchers note, “Several large vaccine trials have reported statistically significant reductions in antibody levels when antipyretics were used at the time of vaccination.”¹⁵ If the goal of vaccination is to increase antibody production, fever reducers taken following vaccination directly interfere with this goal.

 

 

Starve a Cold, Feed a Fever?

What to eat when sick 

Common wisdom advises that you starve a cold, but feed a fever. The reasoning is that your body burns more calories when you have a fever and it needs fuel. But this is not the best advice. When the body is fighting infection, digestion slows, so it’s better to eat lightly, or not at all. Instead, support your body’s efforts to get well by keeping well hydrated. Drink plenty of water and get lots of rest. Water with lemon juice, vegetable broths or freshly made juices can provide nutrients without taxing the digestive organs. 

 

 

 

When To Go To A Doctor For Fever

Although a fever is usually not a serious cause for concern, in some rare circumstances, medical attention should be sought, so be sure to monitor the situation. Here are signs that indicate medical help is needed.¹⁶

 

Babies and children

Age	Temperature	What to do
Less than 1 month	100.4° F (38° C)	Get immediate medical care. Breast feed as often as baby desires. Breast milk can stimulate the immune system and provides antibodies.
1 to 3 months	100.4° F (38° C) If baby appears ill (see below for signs of illness)	Seek medical attention. Breast feed as often as baby desires.
3 months to 36 months	102.2° F (39° C) If child appears ill (see below for signs of illness)	Seek medical attention.
All ages	103° F (39.4° C)	Seek medical attention.

 

All ages

At any temperature, if your child seems  listless,  confused,  doesn’t make eye contact,  is irritable,  vomits repeatedly,  has symptoms that cause a lot of discomfort,  has a rash,  does not urinate or experiences burning during urination,  has a fever that lasts longer than three days,  has a seizure that lasts more than 5 minutes, or  doesn’t recover quickly from a seizure.

Seek medical attention.

 

Adults

Talk to a health care provider if your temperature is 103 ° F (39.4°  C) or higher. See a medical practitioner if your fever lasts more than two days or if you have a fever along with any of the following symptoms:

 

• Severe headache
• Pain when urinating
• Abdominal pain
• Burning during urination
• Difficulty breathing or swallowing
• Stiff neck and pain when you bend your head forward
• Rash
• Unusual sensitivity to bright light
• Mental confusion, strange behavior or altered speech
• Persistent vomiting
• Convulsions or seizures

 

 

Fever is a sign that the immune system is working as it should. The typical treatment of fever with fever reducing drugs like ibuprofen, acetaminophen, and aspirin in most cases is not warranted based on the evidence and may do more harm than good.