The short answer
Alcohol is the single biggest risk factor for harm in saunas. It lowers blood pressure further, dehydrates you, dulls the warning signs of overheating and can cause heart rhythm problems. In Finland, half of the people who died in a sauna had been drinking. Don't drink before or during a sauna, and wait until it has worn off.
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What does the evidence show?
The clearest data comes from Finland. A study of every death that occurred in a sauna in the country between 1990 and 2002 found that deaths were rare, at under 2 per 100,000 people a year. But half of those who died were under the influence of alcohol, and the authors found the role of alcohol had grown over time. Their main advice: drink less, and never leave someone who has been drinking alone in a sauna.
Why is alcohol so risky in the heat?
- Lower blood pressure. Both heat and alcohol widen blood vessels. Together they make blood pressure fall further, so fainting is more likely, especially on standing.
- Dehydration. Alcohol makes you pee more, on top of the fluid you lose through sweat.
- Heart rhythm. Alcohol and heat both strain the heart and can trigger irregular rhythms.
- Judgement. Alcohol makes you less likely to notice you’re overheating and more likely to fall asleep or stay in too long.
- Falls and burns on wet floors, hot stones and stoves.
What about cold water after drinking?
That’s riskier still. Alcohol worsens the effects of cold water shock and impairs swimming and judgement. Never go into open water after drinking.
What’s the safe approach?
- No alcohol before or during a sauna.
- If you’ve been drinking the night before and feel rough, skip the sauna.
- If a friend has been drinking, don’t let them use a sauna or plunge pool alone.
Keep reading
- Do saunas affect sperm and male fertility?
What happens to sperm count and quality with regular sauna use, whether the effect is reversible and what to do if you're trying for a baby.
- Who should avoid saunas? Heart conditions, medicines and more
Who shouldn't use a sauna, who should check with a doctor first, and which medicines and health conditions make saunas riskier.
- Can you use a sauna when pregnant? UK advice and evidence
Saunas, steam rooms and hot tubs in pregnancy: what the NHS advises, what studies of heat and pregnancy show, and how to stay cool.
Common questions
Can I have a beer in the sauna?
It's a tradition in some places, but it isn't safe. Even moderate drinking increases the chance of fainting, dehydration and heart rhythm problems in the heat. Have water instead and save the drink for later.
How long after drinking can I use a sauna?
Wait until the alcohol has fully worn off, which usually means the next day after an evening of drinking. Your body processes about one unit an hour, but that varies a lot.
Is a sauna good for a hangover?
No. A hangover means you're already dehydrated, and a sauna will make that worse. Rest, drink water and eat something instead.
References
- Kenttämies A, Karkola K. Death in sauna. Journal of Forensic Sciences, 2008.pubmed.ncbi.nlm.nih.gov
- Ylikahri R et al. The sauna and alcohol. Annals of Clinical Research, 1988.pubmed.ncbi.nlm.nih.gov
- Hannuksela ML, Ellahham S. Benefits and risks of sauna bathing. American Journal of Medicine, 2001.pubmed.ncbi.nlm.nih.gov
- NHS. The risks of drinking too much.nhs.uk
First published 4 November 2026. Spotted an error? Tell us and we'll correct it. Read our editorial policy.