Question 1

Is it safe to use a sauna while pregnant?

Accepted Answer

This has been studied, and the numbers are reassuring. A systematic review pooled 12 studies and 347 pregnant women: not one exceeded a core temperature of 39.0 °C, the threshold regarded as harmful to the fetus. The highest single reading was 38.9 °C, and it was measured after exercise — not in a sauna. The review concludes that a pregnant woman can sit in a 70 °C dry sauna (15 per cent relative humidity) for up to 20 minutes at any stage of pregnancy without exceeding that threshold. A Finnish löyly sauna, however, is often hotter and considerably more humid than the experimental setup, and humidity reduces the cooling power of sweating: keep sessions short and mild, drink water, and step out at once if you feel light-headed. Ask your own maternity clinic about your own pregnancy — this page does not know your situation. Two further reviews point the same way: a broad sauna review states that sauna bathing does not influence fertility and is safe during the uncomplicated pregnancies of healthy women, and a second review found no adverse effects of bathing during pregnancy and no teratogenic effect — toxaemia cases excepted.

Question 2

Who should not use a sauna?

Accepted Answer

A peer-reviewed review names three contraindications: unstable angina pectoris, recent myocardial infarction and severe aortic stenosis. The same review also states the other half: the sauna is safe for most people with coronary heart disease whose angina is stable or whose infarction is old. A second review adds that the sauna did not appear particularly risky for patients with hypertension, coronary heart disease or congestive heart failure when they were medicated and in a stable condition — but it singles out one drug group: antihypertensive medication predisposes to a blood-pressure drop after bathing. Anyone who has come down with a cold should avoid the sauna, especially with a fever. And the instruction that applies to healthy people too: alcohol during sauna bathing increases the risk of hypotension, arrhythmia and sudden death, and should be avoided. About your own condition, ask your own doctor — this page does not know it.

Question 3

When should you not use a sauna?

Accepted Answer

Three situations where the sources say no. The first is alcohol: a peer-reviewed review states that alcohol consumption during sauna bathing increases the risk of hypotension, arrhythmia and sudden death, and should be avoided — and in Finnish forensic data from 1990–2002, half of all people who died in a sauna were under the influence of alcohol. The second is illness, especially fever. Anyone who has come down with a cold should avoid the sauna, and the reason is concrete: the physical strain of the sauna may increase the risk of further illness, for example viral myocarditis. The same applies to children: a child with a fever, or who has otherwise fallen suddenly ill, should not be taken into the sauna. The third is not a ban but caution: blood-pressure medication, especially beta blockers — and note that the drop in pressure comes after the sauna, not during it. Then what is not known, because that gets asked too. With a hangover the question is not how you feel but whether alcohol is still in your blood; if it is, the first point applies. Menstruation, a heavy meal, lack of sleep and hard exercise immediately beforehand are not addressed by our sources at all, and there is no safety research on them in a sauna context. "No known obstacle" is not the same as "studied and found safe", and that difference is worth knowing.

Question 4

Can you drink alcohol in the sauna?

Accepted Answer

No. The peer-reviewed review is blunt: alcohol consumption during sauna bathing increases the risk of hypotension, arrhythmia and sudden death, and should be avoided. In an experiment with ten healthy men, the sauna alone left systolic blood pressure at baseline, while sauna and alcohol together lowered it. In Finnish forensic data from 1990–2002, dying in a sauna was found to be rare — fewer than two cases per 100,000 inhabitants per year — but half of all cases were under the influence of alcohol, and the authors note that alcohol’s role as a risk factor has grown. Their own prevention advice has two parts: less drinking, and never leave a drunken bather alone in the sauna.

Question 5

What do I do if I feel faint in the sauna?

Accepted Answer

Sit down at once, or better, lie down — on the floor if there is nowhere better — and ask for help if you need it. Do not stand up and walk out: the mechanism is a posture-related fall in blood pressure, and standing up is precisely the movement that makes it worse. A collapse can be preceded by a general feeling of unwellness, changes in the visual field, swaying, knees giving way, or the sensation of standing on the deck of a ship in a swell. Note the timing too: the situation is often at its worst some time after leaving the sauna, not in the heat itself. People on blood-pressure medication should be particularly careful.

Question 6

How old should a child be before using a sauna?

Accepted Answer

A child tolerates extra heat less well than an adult, and this is not only about babies. In an experiment where children aged 2–15 sat for ten minutes at 70 °C, two of twenty children aged 5–10 fainted and two more felt unwell while cooling down. A seven-year-old is not automatically safe simply for no longer being a toddler. The practical conclusions: short sessions, a lower bench and a lower temperature than for adults, an adult present throughout, and out immediately if the child says something feels odd. A broad review found the sauna well tolerated by healthy people from childhood to old age — but that experiment is the reminder that individual differences are large.

Question 7

Can the sauna-and-ice-hole combination be dangerous for the heart?

Accepted Answer

It loads the heart from two directions in succession, which is why the guidance is worth following. The heat itself raises blood pressure and heart rate by about as much as 60–100 watts of exercise; cold water triggers an involuntary gasp and a blood-pressure surge within seconds. When immersion and breath-holding coincide, the sympathetic cold shock response and the parasympathetic diving response activate at the same time. Researchers call this autonomic conflict and propose — conditionally, not as an established cause of death — that it could explain some deaths recorded as drowning or hypothermia. In a study of 15–16-year-olds, immersion in 2 °C water produced no serious arrhythmias when the head stayed above water; the authors note that the risk could increase if face submersion and apnea are added. So keep your head dry, do not hold your breath, and never go alone. With heart disease or blood-pressure medication, ask your doctor before you try it.

Question 8

Is the sauna safe if I have heart failure?

Accepted Answer

There is randomised evidence, but it concerns a different kind of sauna from the Finnish löyly. In a Japanese multicentre trial, 149 patients with advanced heart failure were randomised to treatment or control: the treatment was a 60 °C far-infrared dry sauna for 15 minutes once a day for ten days, followed by half an hour of bed rest under a blanket. No serious adverse events were observed in either group. This is not the same as an 80–100 °C löyly sauna, for which no comparable randomised trial exists. Review literature reports that the sauna did not appear particularly risky for heart-failure patients when they were medicated and stable. This is not a decision to make from a travel page: ask your own cardiologist.

Question 9

What is löyly?

Accepted Answer

Löyly is the steam created when water is thrown onto the hot stones of the stove. The word is old: its Finno-Ugric root meant spirit and soul, and Hungarian lélek, soul, comes from the same root. So löyly was originally a word about the spirit, not about temperature.

Question 10

How hot is a Finnish sauna?

Accepted Answer

A traditional Finnish sauna is heated to 70–100 °C, and the humidity comes from löyly rather than from the heater. Temperature alone does not describe the experience: the same 80 °C feels entirely different dry and after a round of wet löyly.

Question 11

What is the etiquette in a Finnish sauna?

Accepted Answer

Shower before you go in. Leave your phone outside. Throw löyly in moderation and ask the others before you throw more. Silence is allowed and often welcome. Drink water, step out to cool down between rounds, and do not force yourself to stay — a sauna is not a competition.

Question 12

Are there hot springs in Finland?

Accepted Answer

No. Finland has no geothermal hot springs. The bedrock here is ancient and stable, without the volcanic activity that heats the water in Iceland or Japan. The Finnish answer to the same wish is built rather than natural: the sauna, and the heated outdoor pools some spa hotels keep open through the winter. The one natural water you will be offered in Lapland is cold, and the ice hole is the whole point of it.

Finnish Sauna in Lapland: Types, Löyly and Etiquette