The short answer
Yes, temporarily. In a small Italian study, ten men who used a sauna at 80–90°C for 15 minutes twice a week for three months had a big drop in sperm count and movement. The effects were completely reversed six months after they stopped. If you're trying for a baby, it makes sense to cut back on saunas and hot baths.
On this page
What did the study find?
Researchers at the University of Padua asked ten healthy men with normal sperm to use a Finnish sauna at 80°C to 90°C for 15 minutes, twice a week, for three months. They tested the men’s sperm and hormones before, at the end of the three months, and three and six months after the men stopped.
At the end of the sauna period:
- Sperm count and movement had fallen sharply.
- Sperm DNA packaging and the energy-producing parts of the sperm were worse.
- Hormone levels didn’t change.
Six months after the men stopped, every measure was back to normal.
Why does heat affect sperm?
The testicles sit outside the body because sperm develop best a few degrees below core body temperature. Anything that heats them, including saunas, hot baths, tight underwear and long periods with a laptop on your lap, can affect sperm production for a while. That is why keeping the testicles cool is common advice for men trying for a baby.
What’s the take-away?
- It’s temporary. There’s no evidence of lasting harm.
- It’s a small study. Ten men is very few, but the effect was large and consistent.
- If you’re trying to conceive, especially if it’s taking a while, consider pausing saunas and hot baths for three to six months, and mention it if you see your GP about fertility.
The same review that collected 40 clinical studies of saunas found this was the only one to report a harmful effect.
Keep reading
- 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.
- Alcohol and saunas: why they don't mix
Why drinking alcohol before or during a sauna is risky, what Finnish data on sauna deaths shows, and how long to wait after drinking.
Common questions
Can a sauna make you infertile?
There's no evidence of a permanent effect. In the study that tested it, sperm count and quality recovered fully within six months of stopping. But if you're already having trouble conceiving, heat may be one factor worth removing.
How long before trying to conceive should I stop saunas?
Sperm take about three months to develop. In the Italian study, sperm had fully recovered six months after stopping, and doctors commonly advise men trying for a baby to keep their testicles cool. If fertility is a concern, stopping saunas for three to six months is a reasonable precaution.
Do saunas affect female fertility?
There's no good evidence that they do. Once you're pregnant, though, UK advice is to avoid overheating, especially in early pregnancy.
References
- Garolla A et al. Seminal and molecular evidence that sauna exposure affects human spermatogenesis. Human Reproduction, 2013.pubmed.ncbi.nlm.nih.gov
- Hussain J, Cohen M. Clinical effects of regular dry sauna bathing: a systematic review. Evidence-Based Complementary and Alternative Medicine, 2018.pubmed.ncbi.nlm.nih.gov
- NHS. Infertility: causes.nhs.uk
First published 4 November 2026. Spotted an error? Tell us and we'll correct it. Read our editorial policy.