What to do if you feel faint in a sauna or cold plunge
The instinct on a hot bench is to stand up and walk out. Get low first, then get out slowly to somewhere cool, and know the signs that mean calling 911.
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Short answer: Get low, then get out, in that order. Sit or lie down on the lowest bench or the floor, then leave slowly for somewhere cool and lie down with your legs raised. Early signs: lightheadedness, sounds fading, vision narrowing or greying, sudden sweating or clammy skin, feeling warm, nausea or weakness. Call 911 if you do not start to feel better within 1 to 2 minutes of lying down, if you pass out, or if you feel confused or stop sweating while you are very hot.
If you feel lightheaded in a sauna, the correct sequence is: get low, then get out. Not the other way around.
First-aid guidelines from the American Heart Association and the Red Cross put a safe position first, to lower the risk of getting hurt. Falls are a real source of sauna injuries: of 209 people treated for sauna injuries at an Austrian trauma centre, slips and falls caused 57.5% of the injuries and dizziness or fainting 30%, and most head and face injuries came from dizziness or fainting (Kaiser and colleagues, 2023).
This is the one piece of sauna knowledge worth having in advance, because you cannot think clearly about it once it starts.
Why does heat make you feel faint?
In a hot room, the blood vessels in your skin widen to shed heat, your heart rate rises, and you lose fluid as sweat. That can lower your blood pressure.
In a study of 102 adults with at least one heart risk factor, average systolic blood pressure fell from 137 to 130 mmHg after a 30-minute sauna (Laukkanen and colleagues, 2018). It does not happen to everyone: in another study it stayed at its starting level in the sauna without alcohol (Roine and colleagues, 1992).
Standing up is the moment it can tip over. When you stand, gravity pulls blood into your legs and belly and blood pressure drops, and Mayo Clinic notes that heavy sweating in a hot environment can trigger that drop. A 2026 review says symptoms often come with a change of position, such as standing up or getting out of a bath (Yokoyama and colleagues, 2026).
The heat itself can harm you too. Exposure to heat was the cause of death in 25% of the deaths in Finnish saunas from 1990 to 2002 (Kenttämies and Karkola, 2008). So the goal is to get out of the heat, not to rest in it. Our guide to your first sauna session covers pacing a session.
What are the warning signs?
The early signs, as the AHA and Red Cross guidelines and MedlinePlus list them: lightheadedness or dizziness, blurry or tunnel vision, noises seeming to fade into the background, nausea, a feeling of warmth, sudden sweating and pale skin, and feeling weak.
Every one of those signs means the session is over now. Leaving early is never a failure: Cleveland Clinic says that if you feel unwell, you should exit the sauna and seek medical help.
Some signs mean more than ending the session. If your sweating stops while you still feel very hot, or you feel confused or not yourself, that can be heatstroke: the NHS and MedlinePlus list these as signs to call for emergency help. The same goes for chest pain or a pounding or irregular heartbeat, the NHS says.
What should you actually do?
Low, then out, then cool.
Get low. Move to the lowest bench or sit on the floor, or lie down along the bench if there is room.
Use your muscles. Once you are sitting or lying, cross your legs and tense your leg, belly and buttock muscles. The AHA and Red Cross guidelines say these moves can help: across 11 trials they cut the risk of fainting by about half. Skip them if you also have chest pain or signs of a stroke, and call 911.
Then get out, slowly, to somewhere cool. Do not rush, and do not stay in the heat to rest. People who pass out inside a sauna can get heatstroke (Ylikahri and colleagues, 1988) or burns from lying still in the hot air (Koljonen, 2009). If someone is with you, say something now rather than after.
Lie down somewhere cool with your legs raised about 12 inches, and stay down for at least 10 to 15 minutes before you stand, MedlinePlus advises. If you are pregnant, lie on your side instead, as the NHS advises for a pregnant person who faints.
Sip water only if you are fully alert. Give nothing by mouth to someone who is vomiting or not responding, MedlinePlus says, and Cleveland Clinic says not to drink anything if you suspect heatstroke.
If you are alone, sit or lie down first, then leave as soon as you can do it safely, and call for help if the feeling does not pass. In Sweden, all but two of the people found dead in a sauna were alone (Rodhe and Eriksson, 2008).
Our guide on what to do after a cold plunge covers the equivalent for cold.
When to call 911
Call 911 if the person who feels faint, or who has fainted:
| Call 911 if the person | Source |
|---|---|
| Is not breathing, or is only gasping (start CPR) | Red Cross; NHS |
| Does not come round within 1 minute | Mayo Clinic; NHS |
| Does not start to feel better within 1 to 2 minutes of lying down, gets worse, feels it come back, or passes out | AHA and Red Cross guidelines |
| Has chest pain or pressure, or a pounding, fluttering or irregular heartbeat | NHS; MedlinePlus |
| Has not fully recovered, or has trouble speaking, seeing, or moving an arm or leg | NHS; MedlinePlus |
| Is shaking or jerking, has bitten their tongue, or has lost bladder or bowel control | NHS; MedlinePlus |
| Was hurt in the fall, especially with a head injury or bleeding | NHS; MedlinePlus |
| Fainted while lying down or while exercising | NHS |
| Fainted and is pregnant, over 50, or has diabetes | MedlinePlus |
| Is confused, very hot, or has hot skin that has stopped sweating (possible heatstroke) | NHS; MedlinePlus; CDC |
| Still feels unwell after 30 minutes resting somewhere cool, being cooled and drinking | NHS |
| Is vomiting, cannot keep fluids down, or is getting less responsive | Red Cross |
While you wait: if they are breathing but not responding, put them in the recovery position. Cool them with cool water or wet cloths, cold packs on the neck, armpits and groin, and fanning. Give nothing to drink if they are vomiting or not fully alert.
For heatstroke, the Red Cross prefers putting the person in cold water up to the neck, and the CDC says someone must hold the person the whole time they are in the water. Never leave them alone in a plunge.
After any faint, see a doctor. The NHS says to see a GP if you have fainted, and Mayo Clinic says losing consciousness, even for a few seconds, requires seeing a provider right away.
Feeling faint in the heat at a glance
| Do | Don’t |
|---|---|
| Sit or lie down where you are, on the lowest level | Stand up and walk out |
| Cross your legs and tense your muscles once you are down | Push through to finish the round |
| Tell whoever is with you | Go quiet and hope it passes |
| Lie down somewhere cool, legs raised, for 10 to 15 minutes | Rest inside the hot room |
| Sip water only if you are fully alert | Drink anything if you are vomiting or confused |
| Call 911 if it does not ease within 1 to 2 minutes | Get into a cold plunge on your own |
| End the session for the day | Go back in “just for a minute” |
What about the cold plunge?
Cold water does something different. It causes an instant spike in heart rate and blood pressure, and a gasp followed by rapid, out-of-control breathing, which can make you dizzy and feel faint, the National Center for Cold Water Safety explains.
So do not stand up fast in the tub, and get out deliberately using the steps and the rail. If you feel unwell in the water, get out immediately rather than waiting for the timer.
Getting out can be a risky moment too. People who have been in cold water for a long time can pass out as they are lifted out, probably because blood pressure drops when the water stops pressing on the body, the National Center for Cold Water Safety says.
Your core temperature can also keep falling after you get out: this afterdrop was seen in 10 of 11 swimmers after a San Francisco Bay swim (Nuckton and colleagues, 2000). Those findings come from long swims, not short plunges.
Big temperature jumps strain your circulation. The 2026 review warns that going back and forth between sauna and cold water may put substantial stress on the heart and blood vessels, and advises caution with cold plunges and cold showers after heat. Our guides on the right order for contrast therapy and cold plunge safety cover both.
How do you avoid feeling faint in a sauna?
Go in having had something to drink and eat. Not eating or drinking enough and low blood sugar are both listed causes of fainting, by the NHS and MedlinePlus. Our guide on eating and hydration around a session covers what the sources say.
If you are new to saunas, start with about five minutes and add time each session, as Cleveland Clinic suggests. When you are tired, choose a lower bench and a shorter round.
Skip the sauna when you are ill or hungover. The 2026 review advises avoiding sauna use during acute illness, and a Finnish paper warns that sauna bathing during a hangover creates real health risks (Ylikahri and colleagues, 1988). Our guide on saunas when you are sick covers the line.
Never combine heat with alcohol. Drinking in the sauna raises the risk of low blood pressure, heart rhythm problems and sudden death (Hannuksela and Ellahham, 2001), and half of the people who died in Finnish saunas from 1990 to 2002 were under the influence of alcohol. Our guide on alcohol and sauna covers the evidence.
Who is at higher risk of fainting in a sauna?
Some medicines make a drop in blood pressure on standing more likely, Mayo Clinic notes: medicines for high blood pressure and heart disease, including diuretics, certain antidepressants and certain antipsychotics. The CDC lists antipsychotics such as quetiapine as impairing sweating.
If you take any of them, use lower heat and shorter sessions, and raise it with your prescriber; do not stop or change a medicine on your own. Our guides to wellness on antidepressants, blood pressure medication, quetiapine and sedating medication cover the classes that bring most people here.
Thyroid conditions can also cause a drop on standing, and atrial fibrillation is one of the heart conditions behind repeated fainting in older adults. Our guides to thyroid conditions and atrial fibrillation cover why.
Pregnancy, being 65 or older, and low blood pressure all raise your risk. ACOG advises against saunas early in pregnancy. Our guides on pregnancy safety, starting safely as an older adult, and sauna and the heart cover each.
If you have fainted before and have not been checked, see a doctor: the NHS and the American Heart Association say anyone who faints should be assessed.
For home saunas: never lock the door behind you, and tell someone you are in there. In a public studio, ask whether staff check the sauna regularly; our guide on choosing a studio covers what else to ask. If standing up is the problem even without heat, our guide to wellness with POTS and dysautonomia covers that condition.
FAQ: feeling faint in a sauna
Is feeling lightheaded after a sauna normal? A brief, mild lightheaded moment when you stand up can happen, and Mayo Clinic says occasional lightheadedness on standing is likely no cause for concern. Greying or narrowing vision, sounds fading, nausea or clamminess are different: they mean stop now. If you actually pass out, even for a few seconds, see a doctor.
Should I go back in the sauna after I recover? No. Stop for the day. The Red Cross says to wait several hours after the symptoms are gone before resuming activity, and Mayo Clinic warns that getting up too soon can bring on another faint.
What if someone else faints in a sauna? Get them out of the heat if you can do it safely, and check that they are breathing; if they are not, call 911 and start CPR. If they are breathing, lay them on their back with their legs raised about 12 inches, or on their side if they are pregnant. Call 911 if they do not come round within one minute, or if they are confused, very hot or have stopped sweating, and cool them while you wait.
When should you call 911 for fainting in a sauna? If they do not come round within a minute, if feeling faint does not ease within 1 to 2 minutes of lying down, if it gets worse or comes back, or if there is chest pain, confusion, a seizure, an injury, or hot skin that has stopped sweating. The full list is in the table above.
Does feeling faint mean saunas are dangerous? No. Sauna use is well tolerated by most healthy adults (Hannuksela and Ellahham, 2001), and death in a sauna is rare even in Finland, where sauna bathing is common. Falls and fainting are the injuries to plan around, and alcohol is the risk to avoid.
The bottom line on feeling faint in a sauna
Heat can lower your blood pressure and standing up lowers it further. When you feel faint, get low first, then get out slowly to somewhere cool, and lie down with your legs raised.
Call 911 if it does not ease within 1 to 2 minutes, if you pass out, or if you feel confused or stop sweating while you are very hot. After any faint, see a doctor.
If you are treated for high blood pressure, the exit is the moment that matters most: a Finnish review found antihypertensive medication may predispose to a drop in blood pressure after bathing (Kukkonen-Harjula and Kauppinen, 2006), and our guide on sauna, cold plunge and blood pressure covers the rules that follow from that.
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