There is still much we do not know about the novel coronavirus, COVID-19, but researchers are starting to piece the puzzle together as we go along. For example, a recent Chinese investigation suggests COVID-19 is “highly sensitive” to high temperatures and spreads faster in colder climates; its most rapid spread is occurring at a temperature of 8.72 degrees Celsius.
The researchers recommend countries with colder climates “adopt the strictest control measures” to limit the spread of the disease. Hassan Zaraket, assistant director of the Centre for Infectious Diseases Research at the American University of Beirut, commented on the preliminary findings to South China Morning Post:
“As temperatures are warming up, the stability of the virus could decrease … if the weather helps us reduce transmissibility and environmental stability of the virus, then maybe we can break the chain of transmission.”
You don’t have to wait for the arrival of summer, however, to take advantage of the potential benefits of heat. James DiNicolantonio, Pharm.D., a cardiovascular research scientist at Saint Luke’s Mid America Heart Institute, recently highlighted a core mechanism by which your body fights viral infections, namely fever.
A fever is your body’s way of raising your core body temperature, and most pathogens don’t fare well in high heat. DiNicolantonio argues high heat exposure activates heat shock proteins which may prevent viral nucleoproteins from being exported suppressing viral replication. Thus, sauna therapy may have potential against RNA viruses particularly prior or early on in infection.
Sauna Bathing Lowers Risk of Viral Illness
Ways in which you can acutely and temporarily raise your core body temperature include sauna bathing, taking a steam bath, physical movement to induce sweating, or simply bundling up with warm clothes. In a March 16, 2020, Instagram post, DiNicolantonio explainsed:
“I have been getting a lot of questions about the [Joe Rogan] podcast on coronavirus. A lot of people were disappointed to hear that Michael Osterholm suggested saunas would not work against coronavirus. Michael argued that the lungs wouldn’t get hot enough in a sauna to kill coronavirus.
The problem is that he is looking at this from the WRONG mechanism. Saunas increases CORE BODY TEMPERATURE. Remind me again how our body fights off viruses? That’s right! By raising core body temp-DEVELOPING A FEVER! Why does our own body do this? Because a FEVER HELPS COMBAT VIRUSES.
Saunas, especially infrared saunas, create a ‘pseudo fever’ by raising core body temp. So how do fevers (or saunas) potentially work against viruses? By increasing HEAT SHOCK PROTEINS. So, saunas’ inability to increase the lungs to 180 F is NOT a reason to argue that it won’t help against viral infections.”
I would add that DiNicolantonio’s advice on saunas is spot on, but electromagnetic fields (EMFs) are not his specialty. While infrared (IR) saunas are helpful, one needs to be diligent about the electric and magnetic fields.
While many newer IR saunas have low magnetic fields of about 1 milligauss, many have electric fields far higher than the recommended 30 volts/meter. One that advertises themselves as low EMF I measured at 700 volts/meter. So, do your homework before you use them.
Antiviral Effects of Sauna Bathing
A number of studies have investigated the antiviral effects of sauna bathing. For example, a clinical study involving 50 volunteers showed regular sauna bathers had half the rate of common cold compared to nonusers.
This makes sense, considering sauna use will kill bacteria, fungi, parasites and viruses and boost your immune function by increasing white blood cell, lymphocyte, neutrophil and basophil counts. As noted by DiNicolantonio, “prospective studies [show] that those who use a sauna ~2-3 times per week have a lower risk of getting colds, influenza and pneumonia.”
He also cites research showing animals placed in a sauna before being injected with influenza virus had dramatically reduced lung pathology and mortality. Viral replication was also suppressed in sauna-exposed animals. A German review of the benefits of sauna bathing further notes (translated to English)
“Regular visits to the sauna significantly reduce the frequency and severity of influenza infections in children and adults. In athletes (medium-distance runners compared to untrained), the immune system is apparently more stimulable.
In the Second World War, among the Finns, confidence in the effects of saunas went so far that they were used as the main measure for preventing typhoid fever.”