Fever

Feed a cold, starve a fever

There’s a great Calvin and Hobbes cartoon where the little boy is staring at a cow, particularly its udder. And he remarks that you have to wonder who looked at that and thought, whatever comes out of that, I’m going to drink it.

Where do some of these things come from?

We ask because eating is pretty simple when you come down to it. If you’re hungry, eat. If you’re not, don’t. Humans (and animals) have been doing it for years. And there are no animals out there giving each other instructions on how to eat if they’re sick. We imagine if they’re hungry, they eat, and if they aren’t hungry, they don’t.

Anyway, at some point, we humans decided we knew better. And we started dispensing this gem. Some believe the origins of this date back to the 1500s, when John Withals, who wrote dictionaries, penned, “Fasting is a great remedie of feuer.” Others have hypothesized that eating generates heat, which would be bad in a fever (when you’re hot), but good when you’re cold. Unfortunately, when you have a cold, you’re not necessarily cold in temperature, but logic never stopped any of these myths before.

This is an amazing thing about some of these myths. Even though there is no good reason to believe the idea at face value and no reason to think that the rest of the animal world has been suffering because they lacked such wisdom, we believe in the idea so strongly that we try to prove it true.

This has led to a number of studies trying to see if eating or not eating affects the immune system. A study of six (yes, only six) healthy men found that nutritional status did change the balance of T helper 1 (Th1)–Th2 cells. Moreover, eating resulted in increased levels of gamma interferon, while food deprivation increased interleukin-4 release. In this small study, eating did result in some small changes in the cells of the immune system.

This study did not look at people who had colds or fevers, it did not test any hard outcomes such as whether people get better or not, and, we reiterate, it was a study of just six healthy males. To counter it, we would offer hundreds of millions of years of evolution of animals eating when they are hungry and not eating when they are not.

We suspect that many people will continue to believe this myth. In fact, if you search the literature thoroughly—and we did—you will find a number of articles that continue to offer hypotheses for why this advice is sound. It’s important to note, though, that nearly all of these articles state right up front that they are guesses. They aren’t studies proving this myth is true. They are attempts to imagine scenarios as to why it might be true.

But that’s not research. That’s not evidence. There are no studies whatsoever showing that feeding a cold or starving a fever does any more good than harm. The body continues to need fluids when it is sick, but food it can do without for short periods of time. So we say, when you are sick, you should eat when you’re hungry! If you’re not hungry, wait until you are. Common sense.

If your temperature hits 104, you are going to have brain damage

Of all the symptoms of illness, none seems to inspire panic and concern more than a fever. Parents especially seem madly concerned with the temperature of their children. While some are willing to ignore all sorts of complaints and issues, almost no parent will ignore a bump in temperature.

This problem with fixating on the temperature as a number is that it misses the holistic picture of health and illness. It also causes plenty of needless worry as mothers and fathers watch over their children with rising temperatures, as if by will they could cool them.

In general, fever is just one more symptom of being sick. Like a cough, it is part of the body’s armament for fighting infection, not some evil harm dreamed up by devilish germs. The body is usually kept in the range of 98–99 degrees; the idea that all humans exist at 98.6 degrees at all times is actually a myth. In fact, the normal temperature of babies and small children can vary from 97 to 100 degrees depending on the time of day, whether they have eaten recently, or what activities they are engaging in. Anything below 100.4 degrees Fahrenheit is usually not acknowledged as a fever by medical personnel.

The hypothalamus is part of your brain that works (among other things) as your body’s thermostat. Fever is caused when the hypothalamus resets your body’s temperature. When you are infected with bacteria or viruses, your white blood cells will release a compound called interleukin-1, which alerts the hypothalamus to raise the temperature in your body. Those chills you feel? That shivering that concerns so many of you? Those are part of the way the body gets the job done to fight infections. Raising the temperature is thought to help weaken the germs’ capabilities and bring about their death.

Antipyretics, or drugs that help bring down a fever, do so by lowering the hypothalamus’s thermostat. The usual drugs to lower fevers are acetaminophen (Tylenol) and ibuprofen. And there is usually nothing wrong with giving these drugs to someone who has a fever. If you have a young baby, you should always talk to a doctor before giving them medicines, but in general, no studies have shown that using medicines to lower your temperature back toward normal will hinder your body’s immune system.

Now, back to the numbers. Generally, adults feel worse when they have fevers than do children. An adult with a fever of 104 will usually feel very ill, but 104 is still not high enough to cause concern about potential brain damage. It is highly unlikely that brain damage will occur until your temperature goes over 107.5 for an adult and 106.5 for a child.

That almost never happens. That’s because your hypothalamus is in control of your body’s temperature. It’s not that the infection is driving your temperature up and your body is fighting it. Your body is driving the temperature up on purpose, on its own. And the temperature is not going to be set that high by the hypothalamus. In order to hit temperatures that high, usually something else has to be seriously wrong. If you’re seriously dehydrated, for example, your body may not be able to cool itself. If you wrap a child in tons of blankets, then the child also could be in danger because they would not have the ability to cool themselves adequately.

This brings us to some things you should not do in an attempt to bring down fever:

Do not try to cool a child with rubbing alcohol. Children can actually absorb the alcohol through their skin, and that is bad.

Do not try to cool a person down with ice water; that’s counterproductive.

Do not even try to cool them down with lukewarm water until some time after you’ve given them antipyretics. If you try and cool them before the hypothalamus has reset itself, you will just be fighting the body as it works in the opposite direction to get the temperature back up.

People do worry that if a temperature goes too high that they might have a seizure. It is true that febrile seizures do occur, but most people now believe that the actual value of the temperature has little to do with seizing. The vast majority of febrile seizures occur at temperatures below 104.

Most important, don’t become so fixated on the temperature that you forget to look at the whole picture. Some children with a temperature of 104 can look amazingly well and just have a mild illness. Others can have a temperature of 102 and be seriously ill. Don’t overemphasize the fever. It’s just one more symptom, and it’s very unlikely to cause harm.