Natural Variations in Temperature
Although the core temperature of 98.6°F is presented as a stable value, it can vary slightly depending on various factors.
On waking up from a full night’s sleep, the core temperature is around 97.7°F. This is a bit lower than the temperature of the body for most of the day, which is explained by the fact that the body functions at a slower rate during the night. At the end of the day, the opposite is true, and the temperature is slightly higher at 99.5°F. This is because the body has collected heat generated by its physical activities over the course of the day. This means there is a normal deviation of almost a degree on either side of the optimum temperature of 98.6°F. This is a minimal distinction, but larger deviations are possible.
When temperature deviations are evident on the low end of the scale, with body temperatures around 96.8°F and even as low as 95°F on a daily basis, it can indicate a state of permanent hypothermia. These are people whose vitality has been greatly diminished following a long illness, a protracted and exhausting activity, long periods of hardship and deprivation, or with age or certain diseases such as cardiac disorders, which reduce the oxygenation of the tissues and consequently reduce the intensity of the metabolism in general.
The core temperature cannot fall much lower than this without serious consequence; 86°F qualifies as life-threatening, severe hypothermia, with symptoms such as loss of muscle coordination and even loss of consciousness. In exceptional cases, individuals whose body temperatures have fallen as low as 68°F following prolonged exposure to the cold—boating accident victims and mountain climbers—have been saved and brought back to health. But these are very rare cases.
Nonetheless, in certain surgical procedures the body temperature is intentionally brought to the critical 86°F mark for a brief period of time in order to slow blood circulation and metabolic activities. The temperature of a single organ may be brought down even further during certain operations, sometimes as low as 50°F; this is therefore localized hypothermia and not a general case.
Temperature deviations upward (hyperthermia) are also possible, but the body is unable to tolerate as much upward deviation. A rise of several degrees and the body reaches its upper limit of 109.4°F, after which death ensues.
NATURAL AND PATHOLOGICAL HYPERTHERMIA
Naturally occurring hyperthermia is the result of intensified physical activity. For workouts and sporting activities, a temperature between 101.3°F and 102.2°F is considered optimum for the flexibility of the muscles and tendons. The core temperature can rise as high as 104°F with strenuous activity, which is not optimum but still acceptable.
A large production of heat and an increase in body temperature will also occur during a large meal accompanied by alcohol, as this makes a great demand on the forces of the body. It is common to see diners who are flushed and even perspiring.
Sauna is another practice that causes a rise in body temperature. Enveloped in air that often ranges between 176°F and 212°F causes the body to collect large amounts of heat without the possibility of losing very much of it. Adding this heat to the existing body heat induces hyperthermia.
A common characteristic of these different forms of hyperthermia is that they are only temporary and do not last for long periods of time. After a maximum of several hours after the activity has ceased, the optimum temperature of 98.6°F will return.
The same cannot be said for hyperthermia of pathological origin, in other words, fevers. Fevers, with their characteristic ups and downs, do extend over longer periods of time, and can last for several days or weeks.
FEVER
Strictly speaking, we are dealing with fever when—because of an illness—the body’s core temperature rises more than 1.8 degrees above its normal temperature.
When the temperature range falls between 99.5°F and 100.4°F, we are dealing with a sub-feverish condition or febricule. The onset of genuine fever is defined as starting at 100.4°F. Fever is more or less intense depending on how much higher than normal body temperature it has become. Temperature in the range from 100.6°F to 101.3°F is described as mild fever. Higher than this, up to 102.2°F is moderate fever. A strong fever is a temperature of 102.3°F or higher, and a severe fever is 104°F or higher. While fever spikes of between 105.8°F and 107.6°F can be tolerated, anything over 109.4°F will be fatal.
Mild fever: 100.6°F to 101.3°F
Moderate fever: 101.4°F to 102.2°F
Strong fever: 102.3°F to 103.9°F
Severe fever: 104°F and higher
During a fever, the temperature of the peripheral layer of the body is the same as the core temperature; whereas, under normal conditions it is always slightly lower. With the core temperature of the body extending all the way to the surface, the entire body is bathed in an intense heat, which it can barely tolerate—especially when the temperature is quite high and lasts for extended periods of time (see figure, page 16).
These high temperatures bring about functional disorders, with disruption of enzymatic activity, blood circulation, cellular exchanges, nerve transmission, and muscular contractions. If severe fever continues, the heat will cause the macro-proteins of the body organs to break down, forming lesions. The lesions will not allow the organs to function properly, and death will soon follow.
THE CAUSES OF FEVER
There are numerous causes of fever, the best known being microbial infection. The bacteria, viruses, funguses, and parasites that are able to find a way into our bodies are the source of many diseases. Poisoning, allergic reactions, and the presence of cancerous cells are additional causes of fever. Overeating and physical exhaustion are also common culprits.
What do these various causes have in common? Germs, poisons, allergens, toxins, and so forth all threaten the proper functioning of the body and its very survival. All of these substances and conditions, diverse as they may be, oblige the body to react in order to protect itself from their harmful influence. The reaction of physiological defenses consists first and foremost of neutralizing and eliminating anything that represents a danger.
Microbes themselves are a danger because they destroy whatever tissue they colonize. Because they are living beings, they also expel excrement into our bodies. Their waste products overwhelm the body either because of the mass they represent—although germs are tiny, during an infection they quickly multiply and become numerous—or because of their toxicity. Some of these germs are true poisons for our cells; for example, the toxins of Clostridium tetani, which are responsible for tetanus and which destroy the nerve cells of the spinal column and muscles.
The mineral, plant, and animal substances responsible for poisoning people, like caustic soda, for example, or mushroom toxins or snake venom, are harmful to the body by definition because they either disrupt its proper functioning or attack its tissues. Allergens are dangerous because of their specific characteristics and the wide range of physiological and chemical reactions they cause; cancerous cells release dangerous poisons; overeating creates massive amounts of metabolic residues and wastes; and mental and physical overexertion, too, threaten health because of the wastes they produce, which cannot be eliminated by the body in a timely manner.
Fever is therefore not a symptom that is imported by the poison or germs but the expression of the body as it confronts this attack. Fever is not an independent entity that comes from the outside; it develops in response to an external threat. This explains why fever is present in so many different kinds of diseases and disorders.
To really understand how the body “makes” a fever, we must first take a good look at a fundamental notion of natural medicine, that of the biological terrain.
THE BIOLOGICAL TERRAIN
The body will be able to function properly, which is to say, enjoy good health, only if its organs are working normally. These organs can work well only if the cells they consist of are able to faithfully perform their duties. This capability depends entirely on the organic fluids in which the cells are immersed.
The cells are entirely dependent upon these fluids: they are the source of their nutrition, the means for transporting their wastes away, and their medium for transferring information. In fact, cells are entirely surrounded—inside and out—by fluid. This vast ocean in which they live consists of blood, extracellular fluid (which surrounds the cells), and intracellular fluid (with which they are filled). All together, these liquids make up what is known as the biological terrain—the internal cellular environment of the body. And just as a plant can thrive only in soil or a terrain possessing very specific properties, cells can live only in a suitable biological terrain.
There is an ideal composition of these bodily fluids that allows the body to function at its optimum level. Consequently, the balance of health is threatened by each and every qualitative change of this composition. Two principal alterations may occur:
In the first case, we are dealing with deficiencies; in the second case, the clogging and fouling of the terrain by toxins. This clogged and fouled state of the terrain is regarded in natural medicine as the primary cause of disease.
These wastes can irritate the cells causing inflammation or sclerosis, or they can obstruct and smother them. They make the blood thicker, clog blood vessels, and cause congestion in the organs. They disrupt cellular exchanges. The basic problem of ill health is found first in the biological terrain. It becomes visible on the “surface” only later when dysfunction becomes apparent in one part of the body or another.
ILLNESS: A DEFENSIVE REACTION
The body does not remain a passive spectator to the invasion of its tissues by wastes and poisons. It reacts and seeks to rid itself of them by either eliminating them from the body or by burning them on site.
Eliminations take place thanks to the excretory organs, which filter wastes from the blood and lymph and then expel them from the body. These organs include the respiratory tract, skin, liver, intestines, and kidneys. The eliminations that result from the increased labor of these organs are exhibited in catarrhs affecting the respiratory tract (runny nose or sinus, expectorations); eruptions on the skin (pimples, acne, eczema); diarrhea, vomiting, or bile attacks; increased urination and urine that is thick, acidic, irritating, and dark.
The second means the body has at its disposal for ridding itself of wastes is to “burn” them, breaking them down into smaller particles that will be easier to eliminate. These combustions are achieved through increased oxygen intake and increased enzymatic activity. In turn, this necessitates and triggers an accelerated rate of exchanges and an increased speed of blood circulation and respiratory rhythm. The overall intensification of the metabolism engenders an increase in body temperature, in other words, this causes a fever.
WHAT HAPPENS DURING A FEVER?
What happens during a fever, when the body defends itself against an attack? Let’s first take the case of a fever caused by microbial infection before we look at those caused by poisons or toxins.
As soon as the immune system detects an infection, it activates the body’s natural defenses. This automatically causes an acceleration of blood flow through the vessels and, consequently, also increases the heart rate. The acceleration of blood circulation ensures the rapid transport of the body’s defenders from the place they are produced to the site of infection. There is little use in having an army of soldiers if they are not on the battlefield.
Among these defenders that have to be transported are the macrophages, large cells that destroy germs by swallowing them whole, later digesting them in a process known as phagocytosis. Macrophages normally reside in the tissues. In the event of an infection, they have to travel through the extracellular fluid and lymph to reach the site of the infection, whereupon they can spring into action. Microphages are smaller in size but act in the same manner. They primarily reside in the blood. The blood flow carries them to the site of the infection where they leave the vessels and enter the affected tissues in order to absorb the germs that they find there.
T lymphocytes and K lymphocytes (also known as T cells and K cells) are another kind of soldier used by the immune system to destroy germs. A product of the lymphatic system, they are transported to the field of battle first by the lymph then by the bloodstream. These T lymphocytes and K lymphocytes attack microbes in close combat. There are other such agents, like the B lymphocytes (or B cells) that act from a distance. B cells produce antibodies, special substances capable of killing the germs responsible for an infection. But these highly effective substances must be carried to the germs, and at the quickest speed possible; microbes have a vexing property of multiplying at great speed and to such proportions that they are beyond the body’s ability to produce enough lymphocytes and antibodies to fight them. Here again, an extremely rapid means of transport is essential, which is achieved by the acceleration of blood flow.
In order to speed the rate of blood circulation, the vessels contract but, more importantly, the heart starts beating at a higher rhythm. While normal cardiac rhythm is 60 beats per minute, during a fever it can elevate to 100 beats per minute or higher. The increased labor of the heart muscles produces heat that contributes to the rise of body temperature. As the bloodstream and everything it transports (red blood cells, platelets, etc.) flows through, rubbing against the vessel walls, more heat is produced. This circulatory escalation is visible on the outside: the individual’s skin becomes flushed.
A similar acceleration takes place in the lymphatic system. Normally lymph flows quite slowly through the lymphatic vessels. However, since these vessels are connected to the circulatory system (lymph is continuously flowing into the bloodstream at the level of the subclavian veins) lymph flow speed is dependent upon that of the bloodstream. Now, if the normal lymph output is around 1 quart every twenty-four hours, during a fever it is closer to 2 to 5 quarts that can be discharged into the blood circulation daily. Here, too, the acceleration of movement in the lymph vessels produces heat.
The organs of the body work together, each stepping in at a precise point in the metabolic sequence. They are each dependent upon one another and must adapt to the activity of their peers. As a consequence, when one of these organs accelerates the speed at which it performs its function, the other organs must do the same. When the heart increases its rhythm, the lungs are forced to increase theirs. Inhalations and exhalations follow each other at a higher rhythm and with greater breadth, which allows for better oxygenation of the blood and faster elimination of carbon dioxide and the wastes it is carrying.
The quantity of undesirable substances the bloodstream transports is greatly increased during a fever. Dead germs are not the only wastes to be eliminated. If an infection was able to develop in the body in the first place, it is because the biological terrain was overrun with metabolic residues and toxins from environmental pollution and the thoughtless ingestion of alcohol, tobacco, drugs, or pharmaceutical medications. All of these harmful substances, which, by creating a favorable environment for germs, have allowed this infection, should also be eliminated. The excretory organs, such as the liver and kidneys responsible for purifying the blood, as well as the sudoriferous and sebaceous glands of the skin, must consequently also escalate their filtering activities to quickly expel wastes from the body. This escalation is yet another source of heat production, which, when added to the others, helps raise the temperature of the body.
The largest wastes in the body must be reduced into smaller particles before they can be expelled by the excretory organs. The “digestion” of these wastes takes place by virtue of a physiological process called autolysis in which enzymes break down or destroy them. Countless enzymes throughout the body contribute to this effort, which is also a producer of heat.
In non-infectious fevers—those due to poisoning, overeating, or overwork—the same phenomena take place, although the activity performed by the immune system is a bit more modest. The bulk of the heat engendered will come from autolysis, eliminations, and an overall escalation of metabolic activity.
In summary, we can say that the acceleration of combustions, oxidations, exchanges, transport, purification, eliminations, and so forth that is a natural part of the body’s defense process, produces heat, which leads to an elevation in the temperature of the body—in other words, a fever.
To provide a more complete picture, I should also point out that certain germs and white blood cells secrete pyrogenic (fever-inducing) substances. These throw off the body’s thermostat, the temperature regulation center located in the hypothalamus. Now adjusted to a temperature higher than the normal 98.6°F to 102°F, for instance—the pace of all metabolic activity escalates to obtain a corresponding body temperature. Generally this irregularity is presented as detrimental, but shouldn’t we instead view it as help from nature? By pushing the body to raise its temperature, the microbes are in fact activating the defense system that will bring about their destruction.
THE DIFFERENT KINDS OF FEVER
Because fever is the manifestation of the body’s defensive reactions against attack, it does not always appear in the same way. To the contrary, there are numerous different forms fever can take depending on what kind of defensive reactions are implemented by the body.
High or Low-Grade Fevers
Generally speaking, people with strong vitality will experience much more violent and aggressive fevers. They will have a more intense defensive reaction, because they have much more strength at their disposal for guiding it to the best conclusion. A patient lacking vitality, whose body has only a minimal amount of strength for fighting this battle, will produce a weakened defense reaction. Children generally produce higher fevers while the elderly have fevers of much less intensity, because children have more vitality to draw from.
The intensity of the fever also depends on how dangerous the infection is. The more harmful the germs can be to the body and the greater their population, the more likely the body is to react against them in force. If the infection is relatively benign and microbes are not present in large number, the reaction will be reduced proportionately.
Gradual or Sudden Fevers
In gradual fevers, the germs multiply slowly. The microbial invasion is occurring gradually and consequently the problems it causes appear little by little. The fever will take several days to reach its height, and the patient’s state follows this evolution. In the beginning he has only slight discomfort brought on by the infection; but this increases from day to day along with the fever.
Abrupt or sudden fevers appear in an entirely different fashion. Here, the multiplication of germs is quite rapid and all the problems and dysfunction caused by the infection appear quickly, suddenly and radically altering the patient’s condition. In an hour’s time the patient’s temperature can shoot up from 98.6°F to 103°F or 104°F. In parallel to this, the state of the infected person can go from normal to the most intense discomfort the disease is capable of producing. This is the case, for example, with yellow fever, an illness that normally rages in certain tropical regions, but it can also be seen in certain kinds of flu.
Fevers That Plateau or Fevers That Climb Up and Down
Fevers that plateau, with the temperature remaining stable all day, are rather rare. Such a fever would allow us to presume that the microbial threat remained unchanging in its nature, thus the defensive reactions of the body did not differ in their intensity.
Most often, though, the threat posed by germs varies over time. A real battle is taking place between the body and the germs. During these combats, when the winning side begins to tire, the other side can gain the upper hand. Fevers that climb and fall are thus revealing the status of the battle taking place inside the body. If the fever is high, or climbing, it shows that the body is under heavy attack and is strongly fighting back. If the temperature is low, or falling, it means that the germ threat is momentarily vanquished, and the danger it poses is reduced.
Short or Extended Fevers
A fever of short duration shows that the body has quickly neutralized an infection. The defensive mechanisms shut down, because the threat they were responding to has vanished.
When a fever lasts for an extended period, it is a sign that the body has not yet managed to completely defeat the infection, and the defense system must continue its efforts.
Recurring Fevers
Sometimes feverish bouts can recur several times after periods of complete remission. In these cases, although the infection has been properly fought—hence the period of remission—some of the germs responsible for the infection have survived and remain in the depths of the tissue in a dormant state. With the right conditions—such as deterioration of the biological terrain after a period of overwork, intense stress, or a large shock—the germs can emerge from their slumber. Finding themselves in more propitious surroundings, the germs begin to multiply and trigger a new infection.
Intermittent/Relapsing Fevers
These are also bouts of fever that reappear on several occasions but without being separated by a true period of complete remission. The patient has not completely gotten rid of the illness, but her state has temporarily improved between each episode of fever.
These kinds of fever occur when the germ responsible for the infection is difficult for the body to completely destroy and is one that reproduces cyclically. This is the case for the Plasmodium parasite, which is responsible for causing malaria. It colonizes the red blood cells in the bloodstream and multiplies there in vast numbers. After a period of several days, the red blood cells rupture, releasing the parasites back into the bloodstream where they can infect more red blood cells.
The body’s defense system is most effective in killing parasites when they are in the blood, not when they are inside the red blood cells. Therefore, the body has strong defensive reactions when the bloodstream is invaded by these parasites and moments of calm when the parasites are inside the red blood cells.
Depending on the specific kind of parasite responsible for causing the malaria, the time necessary for its reproduction and multiplication will be two or three days. The fevers are therefore labeled as tiertian or quartan, as they will appear on the third or fourth days.
Summary
When the organs are actively working to defend the body against a microbial infection or a poison, an elevation of body temperature will result. If this goes higher than 1.8 degrees above the normal temperature of 98.6°F it is called a fever.