Purpose-built sauna underwear with integrated cooling technology. Heat-resistant fabric. Medical-grade ice pockets. Designed for men who take their protocol seriously.
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The Research
A single sauna session at 80-90°C can drop progressive motility 40-60% for up to 74 days, the length of a full spermatogenic cycle. Scrotal cooling not only prevents damage, it can improve markers above baseline.
Not Just Boxers With Ice Packs
The first underwear built for heat. Developed with input from biohackers and longevity researchers.
Specially woven blend that withstands 200°F+ while staying breathable. Built to perform in extreme sauna conditions.
Positioned based on thermal mapping for optimal cooling coverage. Protects what matters most.
Non-toxic gel packs that maintain temperature for 20+ minutes. Reusable and safe for direct skin contact.
Pulls sweat away so the cold stays where it matters. No slipping, no discomfort, just protection.
Designed for your protocol, not against it.
Built into the design
Slides right in
Cool for 20+ minutes
Human testes operate 2-4°C below core body temperature. That's not a bug. It's critical biology. Sperm production shuts down when temperatures rise.
Saunas, hot tubs, even laptops can derail spermatogenesis for months. The current solution? DIY ice packs stuffed awkwardly in your shorts.
There's a better way.
Optimal testicular temperature
Everything you need to protect your fertility during sauna sessions.
Heat-resistant, moisture-wicking boxer with integrated cooling pocket. Built for 200°F+.
Medical-grade, non-toxic gel packs. Stays cold for 20+ minutes. Reusable hundreds of times.
Quick-start guide with optimal timing, temperature, and usage instructions for maximum protection.
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