The common cold, primarily caused by the rhinovirus, is a common viral infection affecting the upper respiratory tract, leading to symptoms like a runny nose, congestion, and general malaise. Since there is no cure, people often seek various methods to alleviate symptoms and hasten recovery. The concept of using heat, particularly from an infrared sauna, has emerged as a popular potential remedy. This article explores the mechanics of infrared saunas and the scientific basis for how heat may interact with the immune system to determine if this approach offers relief.
Defining Infrared Versus Traditional Saunas
Infrared (IR) saunas use specialized heaters that emit light waves, which are felt as radiant heat, directly heating the body rather than significantly heating the air. This method allows the heat to penetrate deeper into the body’s tissues, similar to the warmth felt from the sun, but without harmful ultraviolet radiation. Traditional saunas, also known as Finnish saunas, work differently by heating the air inside the chamber, typically with an electric heater or hot stones, which then heats the user through convection and conduction.
Traditional saunas usually operate at high ambient temperatures, often ranging from 150°F to over 195°F, creating an intense and often humid environment. Conversely, infrared saunas function at a much gentler temperature range, typically between 110°F and 140°F. The lower ambient temperature in an IR sauna makes the experience more comfortable for some people, allowing for potentially longer sessions.
How Heat Affects the Immune System
Exposure to heat, whether from a sauna or a fever, creates a state of hyperthermia, which mimics the body’s natural response to infection. This elevation in body temperature can trigger beneficial changes in the immune system and the physical environment of the respiratory tract. One effect is the increased production of heat shock proteins (HSPs), which help protect cells and boost the activity of white blood cells, the body’s primary infection fighters.
Warmer temperatures also stimulate vasodilation, increasing blood circulation throughout the body, which helps improve the mobility and distribution of immune cells to areas of infection. Furthermore, the common cold virus, rhinovirus, replicates most effectively at the slightly cooler temperatures found inside the nasal passages (around 91°F to 95°F). Raising the temperature in these areas can potentially inhibit the virus’s ability to multiply. The heat may also help relieve common cold symptoms like congestion by promoting vasodilation and assisting with mucociliary clearance.
Evidence and Limitations for Cold Symptom Relief
While the physiological mechanisms suggest a benefit, the scientific evidence specifically supporting the use of infrared saunas to treat an active cold remains limited and often focused on general heat therapy. Studies on regular traditional sauna use have indicated a reduction in the incidence of common colds over time, suggesting a preventative benefit, but these findings do not directly confirm a treatment effect for an acute infection. The direct heating of the body by infrared light is hypothesized to stimulate immune response components, such as CD8 T cells, which combat viral infections.
The lower temperatures of an IR sauna mean that while they are more comfortable, they may not achieve the same intense heat-stress response seen in traditional saunas that reach 170°F or higher. The benefit for active cold symptoms, such as nasal congestion, is likely due to the general warming effect, which can temporarily open airways and loosen mucus, similar to steam inhalation. This symptomatic relief is often temporary, and the sauna does not eliminate the virus itself. Current research on infrared saunas primarily supports a general immune-supporting role and temporary symptom alleviation.
Safety Guidelines for Sauna Use When Ill
Anyone considering using a sauna while experiencing cold symptoms must prioritize safety to avoid worsening their condition. The most significant concern is the risk of dehydration, which is increased by sweating in the hot environment, especially if the person is already running a fever or experiencing fluid loss. Substantial water intake is required before, during, and immediately after a session to replenish lost fluids.
It is recommended to avoid any sauna use if a fever is present, as the elevated heat can dangerously increase the body’s core temperature and exacerbate the illness. Sessions should be kept brief, generally limited to 10 to 15 minutes, to prevent excessive fatigue or overheating. Users should immediately exit the sauna if they experience signs of distress, such as dizziness, lightheadedness, nausea, or a rapid heartbeat. A sauna is best viewed as a supportive measure for mild symptoms, not a substitute for professional medical advice.