A sauna is a specialized room designed for dry or wet heat sessions, typically heated between 70° to 100° Celsius (158° to 212° Fahrenheit). The practice has ancient roots, evolving globally for perceived health benefits. While saunas offer benefits, frequent use also carries potential risks.
Direct Physiological Hazards
High temperatures in a sauna cause significant sweating, leading to fluid loss and dehydration. Symptoms include increased thirst, dry mouth, and reduced urination. Severe dehydration can be particularly dangerous, impairing body function.
Heat can also lead to heat-related illnesses, ranging from heat exhaustion to the more severe heat stroke. Heat exhaustion symptoms include fatigue, dizziness, nausea, headache, and heavy sweating. Heat stroke, a medical emergency, involves a high body temperature, confusion, slurred speech, and hot, dry skin. Contact burns from hot surfaces are also a risk.
Cardiovascular and Circulatory Concerns
Sauna heat increases heart rate and redirects blood flow to the skin, placing demands on the cardiovascular system. Heart rate can rise to 100-150 beats per minute, similar to moderate exercise.
Blood pressure can fluctuate during and after sauna use; it may initially drop due to vasodilation, though some individuals might experience a rise. Exiting the hot environment can cause a sudden drop in blood pressure (orthostatic hypotension), leading to dizziness or fainting. This is particularly relevant for those with existing blood pressure imbalances.
Compounding Factors and High-Risk Groups
Certain medications can influence the body’s response to heat and increase risks associated with sauna use. Diuretics and some blood pressure medications, for example, can exacerbate dehydration or alter temperature regulation. Individuals taking sedatives may also have impaired judgment and a reduced ability to respond to overheating.
Pre-existing health conditions can also elevate the risks. People with heart disease, kidney disease, liver disease, or diabetes may be more susceptible to adverse effects due to impaired thermoregulation or fluid balance issues. Neurological conditions might also affect an individual’s ability to sense and react to heat intensity.
Some populations are more vulnerable to sauna heat. Pregnant individuals should avoid saunas due to the risk of increased core body temperature harming the fetus. Young children have less developed thermoregulation, making them prone to overheating. Older adults, with reduced heat coping ability and pre-existing conditions, also face increased risks of dehydration and heat-related illnesses. Consuming alcohol or recreational drugs before or during a sauna session impairs judgment, hydration, and temperature regulation, increasing the risk of heat-related illness and accidents.
Recognizing Signs of Adverse Reactions
Recognize signs that a sauna session is becoming unsafe. Symptoms include severe dizziness, intense headache, extreme nausea, and confusion. A rapid or irregular heartbeat, sudden cessation of sweating, or feeling faint are also warning signs.
If symptoms occur, exit the sauna immediately. Cool down gradually by resting in a cooler area or taking a lukewarm shower, and rehydrate with water or electrolyte-rich beverages. Seek medical attention if symptoms worsen, do not improve rapidly, or if signs of heat stroke, such as unconsciousness or seizures, are present.