The cold and flu season is upon us. Despite the advances in biomedical research, there is still no effective prevention and treatment because there are so many different strains of these constantly evolving viruses. In addition, these viruses are everywhere! It is far better to strengthen the immune system so that you reduce the chance of getting sick in the first place. After all, viruses can only make you sick if your immune system allows it. In this article, we will discuss how infrared saunas can help strengthen your immune system for the cold and flu season.

How a Fever Improves Immune Function 

When you have an infection, your immune system induces fever in order to stimulate immune function and make the body less habitable for the pathogens.1 Generally, fevers under 104oF (40oC) help the body fight off pathogens without the risk of febrile seizures. In addition, people infected with rhinovirus (a type of cold virus) who used anti-fever medications experienced reduced immune response — they experienced worsened symptoms, took longer to recover from the cold, and were more infectious than those who didn’t use the medications.2 

According to the American College of Critical Care Medicine, fever is defined as a core temperature of 100.9°F (38.3°C) or higher, i.e. just above the upper limit of an average human temperature, irrespective of the cause.3 Infrared saunas can penetrate deep into tissues and raise core body temperature to approximately 102°F (39°C). Although the sauna heats you up differently than a fever does, the increased body temperature can provide many benefits of fever, such as improving immune functions and preparing your body for the cold and flu season. Here are five examples explaining how this works.

Makes antiviral and antibacterial immune responses more efficient

Many aspects of immune function are heat-sensitive and are designed to be mobilized in response to a fever. Specifically, fever-range body temperature causes the body to favor anti-viral and anti-bacterial immune response (Th1) over the antiparasitic or allergic (Th2) immune response. In addition, fever-range temperature helps the immune system better remember germs that you are exposed to, so that the next time you encounter the pathogens, your body can fight them off better.4

In addition to heating the body, near-infrared light also stimulates white blood cells and increases antibodies against germs by increasing cellular energy production.5

Hormesis

The term “hormesis” refers to a small amount of stress that trains the body to get stronger. For example, exercise is a type of hormesis. Many health benefits of saunas are due to hormesis. 

Using the sauna generates heat stress and oxidative stress at the low levels that help the body better deal with these stressors. The heat exposures trigger the production of heat-shock proteins, which help other protein molecules fold correctly. In addition, heat-shock proteins also help the immune system fight off viruses.6 

Too much oxidative stress can damage tissues and immune cells, which reduces your ability to fight infections. The sauna generates small amounts of oxidative stress that increases your cell’s antioxidant capacity, which reduces your risk of getting sick.7 

Anti-aging for the immune system

The immune system, which is continually replenished by immune stem cells in the bone marrow and thymus, is one of the most sensitive systems to aging. This is why people 65 and older are more likely to get sick and develop complications from cold and flu. 

As people age, their immune stem cells have a declining ability to regenerate more white blood cells. Interestingly, photobiomodulation, especially from the near-infrared spectrum, may stimulate the mitochondria of these stem cells and help mitigate age-related immune decline.8

Reducing Stress 

Stress significantly increases the incidences of colds by reducing the antiviral immune system, partly because cortisol suppresses the immune responses.9, 10, 11 Exposure to far-infrared sauna significantly reduces post-exercise cortisol, which may mitigate the immune-suppression effects of stress.12, 13 In addition, you can use infrared saunas to help you get into a relaxed state, which may further help reduce the risk of getting sick from stress. 

Normalizing the Circadian Rhythm and Improving Sleep

Not all sleep is created equal. Deep sleep helps build your antiviral immune system, so you want to increase deep sleep in the winter.14 

During colder months, when the days are shorter and the sunlight is dimmer, your sleep could get thrown off. You may hardly notice it because you are still going to work and sleep on the same schedule, but you may experience changes in mood, fatigue, and more frequent colds partly because you are not sleeping as deeply.

According to board-certified sleep psychologist Dr. Micheal Breus, the steep drop in body temperature in the evening helps cue your body that it is time to sleep. Using the infrared sauna in the afternoon to help you relax before allowing your body temperature to drop naturally will improve your sleep quality. 

Using the Sauna Reduce Incidences of Common Cold

In an Austrian study, 25 healthy subjects who regularly used saunas had significantly fewer episodes of common colds than those who did not.15 This benefit becomes more significant, especially after 14 weeks of consecutive sauna use. Therefore, in order to fully experience the immune-strengthening benefits of sauna use, you want to use it regularly, at least twice a week throughout the year. 

To maximize the synergistic immune-boosting benefits of infrared sauna, use full-spectrum infrared therapy. The near-infrared spectrum can stimulate immune cell growth and activity by stimulating your mitochondria. The mid-and far infrared wavelengths are absorbed by your body, ensuring that you benefit from the immune-stimulating effects of heat throughout your body and improving your sleep. 

REFERENCES

1 A Sahib Mehdi El-Radhi. Fever management: Evidence vs current practice. World Journal of Pediatrics. 2012 Dec 8; 1(4): 29–33.

2 Department of Community Medicine, University of Adelaide, South Australia. Adverse effects of aspirin, acetaminophen, and ibuprofen on immune function, viral shedding, and clinical status in rhinovirus-infected volunteers. The Journal of Infectious Diseases. 1990 Dec;162(6):1277-82.

3 Edward James Walter. The pathophysiological basis and consequences of fever. Critical Care. 2016; 20: 200

4 Sharon S. Evans, Elizabeth A. Repasky, and Daniel T. Fisher. Fever and the thermal regulation of immunity: the immune system feels the heat. Nature Reviews Immunology. Volume15, pages 335–349 (2015)

5 Department of Microbiology, School of Medicine, Keio University. Possible application of the laser in immunobiology. Keio Journal of Medicine. 1993 Dec;42(4):180-2.

6 Gabriele Multhoff. Heat shock proteins in immunity. Handbook of Experimental Pharmacology. 2006;(172):279-304.

7 Shabnam Hajian. Positive effect of antioxidants on immune system. Immunopathol Persa. 2015;1(1):e02

8 Denis Odinokov and Michael R Hamblin. Aging of lymphoid organs: Can photobiomodulation reverse age-associated thymic involution via stimulation of extrapineal melatonin synthesis and bone marrow stem cells? J Biophotonics. 2018 Aug; 11(8): e201700282.<

9 Stone AA1, Bovbjerg DH, Neale JM, Napoli A, Valdimarsdottir H, Cox D, Hayden FG, Gwaltney JM Jr. Development of common cold symptoms following experimental rhinovirus infection is related to prior stressful life events. Behavioral Medicine. 1992 Fall;18(3):115-20.

10 Cohen S1, Tyrrell DA, Smith AP. Psychological stress and susceptibility to the common cold. The New England Journal of Medicine. 1991 Aug 29;325(9):606-12.

11 Areej M. Assaf,⁎ Reem Al-Abbassi, and Maysaa Al-Binni. Academic stress-induced changes in Th1- and Th2-cytokine response. Saudi Pharm J. 2017 Dec; 25(8): 1237–1247.

12 Antti Mero, Jaakko Tornberg, Mari Mäntykoski, and Risto Puurtinen. Effects of far-infrared sauna bathing on recovery from strength and endurance training sessions in men. Springerplus. 2015; 4: 321.

13 Shanshan Shui, Xia Wang, John Y Chiang, and Lei Zheng. Far-infrared therapy for cardiovascular, autoimmune, and other chronic health problems: A systematic review. Exp Biol Med (Maywood). 2015 Oct; 240(10): 1257–1265.

14 Dimitrov S1, Lange T, Tieken S, Fehm HL, Born J. Sleep associated regulation of T helper 1/T helper 2 cytokine balance in humans. Brain Behav Immun. 2004 Jul;18(4):341-8.

15 Ernst E, Pecho E, Wirz P, Saradeth T. Regular sauna bathing and the incidence of common colds. Ann Med. 1990;22(4):225-7.

WRITTEN BY: Sunlighten