Sauna Safety: Who Should Avoid Saunas?

Sauna is generally very safe when used properly. Serious sauna-related injuries are rare in healthy adults. But certain populations need to be cautious, and even healthy people should follow basic safety rules.

This guide covers who should avoid or be careful with sauna, and the safety practices that make sauna use responsible.

The Safety Profile

Saunas have been used safely for hundreds of years in Finland. Serious adverse events are rare. The main risks are:

•Heat-related illness: Overheating, heat exhaustion, or heat stroke (rare with proper hydration)

•Dehydration: Water loss through sweat (easily prevented by drinking water)

•Syncope (fainting): Dizziness when standing up due to blood pressure drop (prevented by standing slowly)

•Cardiovascular stress: In people with uncontrolled heart disease (can be managed by getting medical clearance)

Who Should Be Cautious or Avoid Sauna

Uncontrolled cardiovascular disease

Uncontrolled hypertension, unstable angina, severe arrhythmias, or recent heart attack — get medical clearance before sauna.

Pregnant women

Consult your healthcare provider. Most research shows moderate sauna (15–20 min at moderate heat) is safe in pregnancy, but individual circumstances vary.

Acute illness

If you're actively sick (fever, flu, cold), avoid sauna. Wait until recovered.

People who have consumed alcohol

Never use sauna after drinking. Alcohol impairs thermoregulation and increases dehydration risk dramatically.

People taking certain medications

Some medications (certain blood pressure meds, antihistamines) impair heat tolerance. Ask your doctor or pharmacist.

Young children

Children under 6 should use sauna very cautiously, with shorter sessions (5–10 min) and lower temperatures. Older children (6+) can use sauna safely with supervision.

Core Safety Rules for Everyone

•Never use sauna alone: Especially the first time. Have someone nearby who can help.
•Start with short sessions: If new to sauna, start with 5–10 minutes and build up.
•Stay hydrated: Drink 500–750 ml of water before and after. Dehydration is the #1 preventable risk.
•Exit if unwell: Lightheadedness, nausea, chest pain, or difficulty breathing = get out immediately.
•Don't push through discomfort: Sauna should be uncomfortable but not agonizing. If too hot, leave.
•Stand up slowly: When exiting, stand slowly and hold onto something. Blood pressure drops and rapid standing can cause dizziness.
•Cool down gradually: A cold shower is fine, but avoid extreme cold immediately after sauna.
•Avoid sauna when fasting: Having eaten a light meal in the last 2–3 hours is safer.

Sauna and Special Populations

Older adults (65+)

Sauna is safe and beneficial, but risks increase slightly. Start conservatively (5–10 min at 160–170°F). Stay hydrated. Use with a partner. Get medical clearance if cardiovascular conditions exist.

People with diabetes

Generally safe, but monitor how your body responds. Some people with diabetes have impaired heat sensation. Don't stay in sauna longer than planned. Stay very well hydrated.

People with seizure disorders

Overheating and dehydration can trigger seizures in some people. Use shorter sessions, stay hydrated, and monitor carefully.

People with multiple sclerosis

Heat can worsen symptoms in some people with MS. Individual responses vary. Consult your neurologist and start cautiously with short, cool sauna sessions.

Breastfeeding women

Sauna is safe while breastfeeding. Dehydration through sweating can reduce milk supply, but proper hydration prevents this.

Fertility and Sauna: Important for Men

Men should be aware: testicular heat exposure reduces sperm production. Regular sauna use can temporarily reduce sperm count and motility.

If you're trying to conceive, limit sauna to 1–2 times per week at moderate temperature (70–75°C), or skip sauna entirely during the months you're actively trying. The effect is reversible — sperm production returns to normal within weeks of stopping sauna.