Saunas use high temperatures, typically between 150°F and 195°F, to induce therapeutic sweating. Whether using this heat therapy when ill is advisable depends entirely on the severity and type of symptoms. While a short session may offer temporary relief for mild symptoms like sinus pressure, attempting to “sweat out” a serious infection introduces significant health risks. The body’s ability to manage its core temperature is compromised when fighting a virus or bacteria, making the added thermal stress of a sauna potentially dangerous.
Physiological Risks When the Body is Stressed
The most serious risk of using a sauna while sick is the accelerated depletion of fluid reserves. When fighting an infection, especially if accompanied by fever, vomiting, or diarrhea, the body is already losing water faster than normal. Intense sweating in a sauna exacerbates this fluid loss, significantly increasing the risk of severe dehydration and electrolyte imbalance. This condition can rapidly lead to extreme dizziness, fatigue, and even fainting, posing major safety hazards in a hot, enclosed space.
A sauna session mimics the physiological response to moderate exercise, increasing heart rate and cardiac output. This increased cardiovascular demand places unnecessary strain on a system already working harder to support the immune response. If a fever is present, the body is already attempting to regulate an elevated core temperature. The external heat from the sauna impairs the body’s natural thermoregulatory process and can potentially worsen the fever. It is necessary to avoid the sauna until the temperature returns to a normal range.
Contagion and Shared Space Considerations
A major concern with using public saunas while unwell shifts the focus to public health. Viral and bacterial infections are primarily transmitted through respiratory droplets created by coughing, sneezing, or heavy breathing in an enclosed space. While the high heat may potentially inactivate some pathogens on surfaces, it does not prevent the immediate spread of droplets between users.
If symptoms involve coughing, sneezing, or congestion, the individual is likely contagious and should avoid all shared wellness facilities. Using a public sauna or steam room while symptomatic is considered a breach of public etiquette and poses a risk to other users. The most responsible action is to isolate at home until all acute symptoms have fully resolved.
Safety Guidelines for Very Mild Symptoms
If symptoms are extremely mild—such as lingering muscle soreness or minor residual sinus pressure after the acute phase of an illness—a highly cautious, short sauna session may be considered. For this scenario, significantly reduce the duration of exposure, aiming for a maximum of five to ten minutes. It is advisable to use a lower-temperature environment, such as an infrared sauna, which operates at gentler heat levels.
Strict hydration protocols are mandatory for anyone using a sauna while recovering from an illness. Consume water or electrolyte-rich beverages immediately before and after the session to proactively replace any fluid loss. Users must immediately exit the sauna if any warning signs develop, including nausea, a sudden headache, lightheadedness, or increased shortness of breath. The goal is mild comfort, and any sign of increased discomfort indicates the body is under too much thermal stress.