I know fevers are no fun. Along with body aches and crushing fatigue, fevers are a symptom that we’ve contracted an illness and indicate how hard our body is working to fight the infection. But before you reach for that aspirin or acetaminophen next time you have a fever, hear me out on how and why that heat is good for you, your kids, and overall wellness. The vast majority of fevers are not dangerous or concerning, however, for detailed information on when you should seek medical care for fever, please see the text box at the end of this article.
Many turn to non-steroidal anti-inflammatory drugs (NSAIDs, like aspirin and ibuprofen) or acetaminophen - which reduces fever and pain, but is not an NSAID - for symptom relief during an illness. These medications often make us feel better by reducing body aches, fatigue, and fever, but that relief comes at a cost. There is a robust and increasing body of evidence in the medical literature that using fever-reducing (aka antipyretic) medications to treat viral and bacterial infections often leaves patients worse off than allowing a fever to run its course.
Fevers benefit us by helping fight a wide variety of pathogens. Studies have shown that using fever-reducing medications increases the duration of viral shedding in common colds, lengthens the time parasites persist in malaria patients, and slows healing in people with chickenpox (Eyers et al., 2010, Stanley et al., 1975). When viral shedding increases, viruses are able to reproduce faster and the likelihood of passing the virus to others also rises. Antipyretics have also been shown to increase mortality risk for influenza patients, increase poliovirus replication, and increase the survival of infectious bacteria (Evans et al., 2015). Even though some of these infectious diseases are now rare in the United States, the wide scope of these studies demonstrate the diverse pathogens that fevers help us fight effectively.
Humans aren’t the only species that rely on fever to fight off nasty invaders. Other mammals, reptiles, and even insects have mechanisms to increase their body temperature in response to infection. If their temperature-elevating mechanisms are blocked while fighting off infections, the survival of all these creatures drops drastically (Evans et al., 2015, Eyers et al., 2010).
A self-confessed biology nerd, I find the physiological mechanisms behind the healing power of fever to be fascinating. While increasing our internal temperature makes it more difficult for viruses, infectious bacteria, and parasites to thrive, that’s far from the only way fevers help us fight off invaders. Fevers also stimulate both the innate and adaptive branches of our immune system. Within the innate immune system, fevers stimulate inflammatory cytokine, macrophage, and natural killer cell activity. Inflammatory cytokines are signaling molecules that stimulate our immune systems to jump into action. Macrophages and natural killer cells are two types of white blood cells that engulf and destroy invading organisms early in infections, as well as stimulating more immune activity. All three of these contribute to the destruction of invading organisms, including pathogenic viruses and bacteria. Fevers also stimulate our adaptive immune system using a targeted approach and activate T- and B-cells to attack invading organisms with precision. Though they have a variety of other functions, many T-cells develop specifically to kill viruses. You’re also probably familiar with antibodies, which are produced by B-cells and neutralize infectious bacteria and viruses (Evans et al., 2015).
Fever doesn’t only trigger the immune response, it also helps complete the process and return us to homeostasis or our natural balance. Through sophisticated signaling processes following the activation of macrophages, fever stimulates the resolution of the inflammatory cytokine process, the same process that was initiated by fever, to begin with. Other ways that fevers are thought to help us return to homeostasis are theoretical and still under investigation (Evans et al., 2015).
While the specific cytokines, prostaglandins, and pathways involved have been identified relatively recently, this knowledge is anything but new. Scientific research articles on the negative effects of suppressing fever with medications date back to at least the 1960s. Naturopathic doctors and their predecessors have successfully treated fevers using the gentle application of cool water dating back to at least the 1800s and the practices of Sebastian Kneipp (Kneipp, 1897; Kirchfeld & Boyle, 1994). Hydrotherapy, the therapeutic application of water, continues to be a foundational practice used by many naturopathic doctors to treat fever because it works with the body's innate healing mechanisms instead of against them, and facilitates a return to health without negative consequences. So next time you or someone in your family has a fever, body aches, and fatigue from a viral or other infection, talk to your health care practitioner about how to support your healing without fever-reducing meds. We’ll be happy to guide you through gentle treatments you can use at home to support your body’s return to wellness.
-Dr Elizabeth Smith, ND
Sources: Eyers, S., Weatherall, M., Shirtcliffe, P., Perrin, K., & Beasley, R. (2010). The effect on mortality of antipyretics in the treatment of influenza infection: systematic review and meta-analyis. Journal of the Royal Society of Medicine, 103(10), 403-411.Stanley ED, Jackson GG, Panusarn C, Rubenis M, Dirda V. Increased Virus Shedding With Aspirin Treatment of Rhinovirus Infection. JAMA. 1975;231(12):1248–1251. doi:10.1001/jama.1975.03240240018017Evans, S. S., Repasky, E. A., & Fisher, D. T. (2015). Fever and the thermal regulation of immunity: the immune system feels the heat. Nature Reviews Immunology, 15(6), 335+. https://link.gale.com/apps/doc/A417186895/ HRCA?u=deschutes&sid=bookmark-HRCA&xid=a4f16329Kneipp, S. (1897). My Water Cure (2nd ed.). William Blackwood and Sons.Kirchfeld, F., & Boyle, W. (1994). Nature Doctors. Buckeye Naturopathic Press.
