Heat damages your fertility from one session.
Above 99°F, your fertility starts to decline. In an 176°F sauna your internal core temperature can climb to 104°F. Recovery? Three to six months — every single time.
Source: Garolla et al. (2013), meta-analyses on sauna and male fertility.
Three steps.
That's it.
Freeze ahead, put it on, sauna. The cooling works automatically — no attention or adjustments during your session.
Freeze the insert
1–2 hours in the freezer. Two inserts included, so one's always ready.
Slide into the pouch
An anatomical pocket holds the insert in place — no slipping, no fuss.
Sauna longer, worry-free
Up to 30 minutes of protection. Works in cold plunges too — perfect for contrast sessions.
Sauna Theory™
Cooling shorts.
100% premium cotton. Anatomical pouch. Includes two freezable inserts in an insulated sleeve. Designed for men who take their health seriously.
Thought through. Down to the thread.
Fertility protected
Keeps the testicles around 95°F — the safe physiological zone.
Comfortable longer
No heat anxiety, no interruptions. Up to 30 min per insert.
100% premium cotton
No microplastics through open pores at 194°F.
Freezable insert
BPA-free, non-toxic. Works in a cold plunge too.
Questions we get a lot.
Our answers are based on peer-reviewed studies and our own material testing.
How bad is sauna for fertility really?
Studies show 2+ sauna sessions per week significantly reduce male fertility. Recovery takes 3–6 months — and the counter resets every time you sauna again.
Does the insert last long enough?
The cool pack holds the safe temperature for up to 30 minutes. After that, it keeps thermally insulating against external heat.
Can it go in a cold plunge?
Yes — even better. The cold plunge re-chills the pack. Ideal for contrast sessions.
How do I wash it?
Remove the insert. Machine wash cold. Hang dry or tumble dry on low.
1,169 men went before you.
Finally saunaing without guilt
"My wife and I have been trying for a few months. Every sauna felt like working against it. With this shorts it just feels right. Comfortable, and the pack stays genuinely cold."
20 minutes without wanting out
"I used to tap out around minute 14 because of that smothering feeling. Now I easily do 22. No painful cold — just comfortable."
Smart design
"The insert stays put. No shifting around, no surprises. The cotton feels premium — not the cheap synthetic stuff."