Your testicles aren’t hanging outside your body just for dramatic flair—they’re there because sperm need it chill. Literally. Your testicles operate best about 4 to 6 degrees Fahrenheit cooler than your core body temp, which is why Mother Nature handed them their own personal swing set.

So when you hop into a 180°F sauna and sweat like you’re in a Finnish fever dream, you’re cranking up the heat on your baby-makers. And unlike your Spotify playlist, they don’t love the hot remixes. This kind of heat—whether from saunas, hot tubs, or scalding baths—can fry developing sperm faster than you can say “scrotal hyperthermia.”

• Sperm production slows or stalls. Spermatogenesis, the sperm assembly line, breaks down when testicular temperature climbs to 100.4 to 104°F.
• DNA damage creeps in. We’re talking oxidative stress, DNA fragmentation, and mitochondrial dysfunction. (Yes, it’s as bad as it sounds.)
• Motility and morphology take a hit. Translation: slower swimmers and weirder shapes.

In short, your fertility doesn’t love a heatwave. Especially not a self-inflicted one.

Let’s break down the data. (Don’t worry, we’ll keep it sexy.)

The Italian Job (Garolla, 2013)

Ten healthy guys, two sauna sessions a week for three months. Result? Sperm count dropped by 40%, motility by 30%, and their DNA looked like it had been through a paper shredder. The good news? Sperm count recovery kicked in 3 to 6 months after ditching the sauna.

Thai Heat (Saikhun, 1998)

Thirty-minute daily sauna sessions for up to two weeks. Sperm swam slower but came back strong a week later. Semen volume didn’t flinch. A win for hydration, maybe?

Meta-Analysis Mayhem (2022)

Nine studies. 356 men. Clear and consistent declines in semen concentration, total count, motility, and shape. Semen volume only dropped 0.2–0.4 mL on average—likely from dehydration, not damage.

The HeatSafe Study (Singapore, 2024)

818 men in the tropics. When outdoor temps topped 29.8°C, low sperm count risk shot up by 46%. Doctors recommend avoiding all sources of scrotal heat—saunas, steam rooms, and yes, your laptop if you’re still working crotch-side.

Here’s a fun fact: most of what you see in a typical ejaculate isn’t sperm. In fact, around 95% of semen comes from the prostate and seminal vesicles—two internal organs tucked safely away from the sauna’s blast radius.

That’s why seminal volume and heat exposure don’t usually go hand-in-hand. Unless you’re severely dehydrated (drink some damn water), your load volume won’t take much of a hit.

But if you're dripping sweat and skipping hydration, yes, you might notice a slightly less dramatic finale. And while that's not a red flag on its own, it’s your body's way of saying, “Hey champ, how about a glass of water?”

If you’re thinking, “Wait, what about those sleek red-lit saunas at my bougie gym?”—good news: infrared sauna fertility risks seem a little less scary.

Infrared saunas run cooler (120 to 140°F) and heat your body more from the inside out. That means less direct cooking of your crown jewels. Studies are still limited, but some early signals suggest sperm DNA may hold up better here than in the full-steam traditional setups.

Still, “less risky” isn’t the same as “safe.” If you're actively trying to conceive, maybe skip the whole sweat lodge scene for now.

Whether you’re trying to get pregnant with a partner, using a surrogate, or freezing your swimmers for a future family plan, heat avoidance is a smart move.

Here’s your action plan:

• Take a 10–12 week heat break. Spermatogenesis takes about 74 days. You need a full cycle off the heat to bounce back.

• Sauna addicts, slow your roll. If you absolutely must go, limit sessions to 10–15 minutes once a week max.

• Post-sauna? Go cold. Take a cold shower or plunge to help pull testicular temps back to baseline.

• Watch total heat exposure. That includes laptops on laps, bike shorts, fevers, and even your tightest skinny jeans.

• Hydrate, hydrate, hydrate. Even a little dehydration can thicken seminal fluid and reduce ejaculate volume.

• See a specialist. A reproductive urologist can help decode semen analysis results and create a plan that’s right for your goals.

And if you’re prepping for a clinic test?

• Skip the sauna before semen analysis.

• Follow best practices before sperm test time, including hydration, abstaining for 2–5 days, and chilling—literally.

Cooling off is step one. But while you’re protecting your fertility from heat, don’t forget to support it from the inside too.

Want to power up sperm volume (and taste) while you're taking your scrotum out of the sauna?

Try Popstar Volume + Taste Supplement —a science-backed formula designed to optimize ejaculatory volume, flavor (yep, that too), and overall sperm health.

If you’re not actively trying to have a baby, you don’t need to sprint out of your steam room screaming. Most sperm damage from heat is temporary and reversible. Weekly sauna sessions can even help with heart health, relaxation, and recovery.

But if baby-making is on your 90-day calendar, then yes—ditch the heat. Scrotal hyperthermia can sabotage fertility, especially if you already have borderline sperm parameters.

Bottom line? Keep your balls cool, stay hydrated, and plan ahead. Your future sperm will thank you for not slow-cooking them.