Fever, the raising of the body’s internal temperature, is an evolutionary adaptation for survival that is millions of years old. This response to infection exists in both warm-blooded and cold-blooded animals (cold-blooded animals raise internal temperature with heat-seeking behavior), from mammals to birds, reptiles to fish, and even in insects[1]. A robust fever – within a safe temperature range – increases overall survival during infectious disease, and suppression of fever increases mortality in critically ill patients[2,3]. Fever not only positively influences our immune response, but also has direct effects on pathogenic microbes, making them less infectious[4].

Note: this article refers to fever from infectious causes only. Increased body temperature from other causes (such as heatstroke, drug reactions, cancer, metabolic issues, etc.) are not necessarily beneficial, and are not discussed here.

The information in this article is for educational purposes only and should not be taken as medical advice. If you or a loved one begin to show signs of fever, consult with your doctor or health care provider to determine the best course of action.

Basic Fever Goals and Therapies

The goal of treatment during a fever is to assist the body in moving through illness, resulting in a quick recovery, strengthened immune system and vitality, and lack of negative consequences from the illness. There are some easy and basic guidelines for helping the body heal.

  • In general it is best not to feed a fever during a simple cold, flu, or other viral illness. If you are not hungry, don’t eat. Do not force children to eat if they are not hungry. The body needs energy to mount a proper immune response, and digestion takes energy away from this process.
  • If you do eat, keep it light: no heavy, fatty, oily, or fried foods; no dairy; no junk food or processed food; and no sugar. Stick with plain, minimally seasoned whole fruits, vegetables, and well-cooked grains and beans. Do not eat cold food or raw vegetables, as these take more energy to digest.
  • Stay hydrated with room temperature or warm liquids. Sweating is part of an appropriate immune response and requires adequate fluid intake. Cold drinks are generally discouraged because they lower body temperature, which is the opposite of what the body is attempting to accomplish during a fever. Refrain from drinking alcohol during an active infection, as it is dehydrating and can suppress your immune system.
  • Refrain from using medications such as Ibuprofen, Advil, Tylenol, etc. to lower the fever unless specifically told to do so by your physician. These medications suppress the immune response[5] and act against the natural disease-fighting process of the body. This class of drugs (NSAIDs) can also cause unwanted side-effects (though rare), such as bleeding in the stomach and asthma[6]. Also, as a general rule, never give over the counter (OTC) medication to children under 6 years old without first consulting with a physician. There are safe ways to lower excessively high temperatures without interfering with the immune process: see below.
  • Resting is of utmost importance. The body needs to conserve energy in order to mount an appropriate immune response. Continuing to work or stay active will often prolong the illness and make recovery more difficult.

Temperature in Fevers

What is the ideal temperature for a fever? This depends on the age of the patient, as children have the capacity to mount fevers that are significantly higher compared with the elderly. It is generally accepted that fevers in children are not significant until the body temperature reaches 100.4℉ (38℃)[7]. In adults, due to circadian rhythms and fluctuations in body temperature throughout the day, fever could be considered to be temperatures above 98.9℉ in the morning, and above 99.9℉ in the afternoon[8]. However, other sources also list 100.4℉ as the cutoff point in adults for defining a fever.

In Naturopathic Medicine, fever is always something to be regulated, not suppressed. If the fever is too low, the treatment should be aimed at raising body temperature. If the fever is too high, the temperature should be brought down. However, in modern times, people more frequently mount fevers that are too low; thus, helping the body raise its internal temperature is typically more appropriate than bringing body temperature down.

When Temperature is too Low

According to naturopathic principles, an optimum temperature for fever is 101℉ – 103℉. Many people, especially older patients – but increasingly younger people as well – do not mount a fever that reaches even 100.4℉, much less 101℉ or 102℉. When a fever is too low, the best course of action is to help the body mount a better response by raising body temperature with heating therapies.

Even without the use of a thermometer, an easy way to assess whether heating therapies will be helpful is by determining if the sick person feels cold, or even if they are especially sensitive to cold. The beginning of a fever response is often accompanied by chills: the body raises its resting temperature and begins shivering to generate more heat. This is a sign that adding heat from the outside will assist the body in this process.

Therapies to consider:

  • Avoid cold and wind, and do not get chilled.
  • Cover up with sweaters, jackets, hats, scarves, blankets, etc.
  • Take a hot shower or bath.
  • Drink hot water or herbal teas.
  • Use a heating lamp or other infrared heat source.

Speak with your doctor or medical provider to individualize the treatment. Many providers will be able to advise you over the phone and can give you recommendations for appropriate home care.

When Temperature is Too High

In children who are sick, it is their appearance and behavior that is most important; their exact temperature is less important. Though a commonly held belief is that high fevers are dangerous, brain damage does not occur until 108℉ (42℃), which is a far higher temperatures than most children will ever reach[7]. The American Academy of Pediatrics notes that the negative consequences of high body temperature do not begin until after 41℃ (105.8℉), which makes the cutoff for concern approximately 106℉. It is not recommended to try and reduce the fever if the child’s temperature is below 106℉.

For adults, and especially for critically ill patients, the threshold for danger is lower. For patients admitted to the intensive care unit (ICU) with acute sepsis, mortality increases with body temperatures above about 40℃ (104℉)[8]. Granted, this is in extremely sick patients, but it gives a good guideline for adults during an acute illness. It is not recommended to reduce the fever if body temperature is below 104℉.

Therapies to consider:

  • Excessively high fevers are dangerous and potentially life-threatening. Call your doctor or provider.
  • If at home, a safe way to lower a fever is with a neutral bath: fill a bathtub with water between 91℉ – 93℉, approximately skin temperature. Do not use cold water, as this can create shivering and cause blood to divert away from the skin, trapping excess heat inside the body. Lay submerged in the bath until body temperature drops below 104℉.
  • Make sure to stay hydrated with both water and electrolytes. High fevers are typically accompanied by sweating, and dehydration is a concern.

If the fever does not come down with a neutral bath, if the patient is delirious, or if the patient looks extremely unwell, call their provider or go to the emergency department.

Conclusion

Fever is one of the body’s most important tools for fighting an infectious illness. It is important to assist the body in regulating temperature, whether using heat to increase body temperature, or using cooling methods to bring down high fevers. In order to work with the body’s natural immune processes, it is better not to use antipyretic medications such as Ibuprofen or Acetaminophen. Allow the body to mount an appropriate immune response, and the end result will be increased vitality, a stronger immune system, and overall better health.

Author

  • Dr. Kye Peven, ND, DSOM, EAMP, earned a B.S. from UC Berkeley in Materials Science and Engineering, with minors in Nuclear Engineering and Energy Management, believing that applying his interest in technology would help make the world a better place. He then completed a Doctorate of Naturopathic Medicine (ND) and a second Doctorate of Science in Oriental Medicine at the National University of Natural Medicine (NUNM). Dr. Peven serves as Director of the WSHC Clinical Care Initiative and is the founder and Clinic Director of the WSHC Seattle Clinic.