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KOLDWR

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Sauna is great for you. Brutal on your sperm.

Cooling underwear with swappable frozen packs. Take the full session, keep one area cool.

Peer-reviewed research shows regular sauna use measurably reduces sperm count and motility for weeks after each session. KOLDWR Pro is cooling underwear engineered for the sauna: swappable cold packs, targeted exactly where heat does damage.

How It Works

01
Freeze
Place the gel packs in your freezer for 2+ hours before your session.
02
Insert
Slide a frozen pack into the sewn in front pocket. It locks in place and sits comfortably against your body.
03
Protect
Enjoy your full sauna or steam room session with hands-free cooling that stays exactly where you put it.

Why longevity optimizers cool down in the sauna

Cooling the groin during heat exposure spread through sauna and longevity communities as a DIY workaround. KOLDWR is a cooling boxer brief built for it.

Why not just rig an ice pack?

The DIY trick works until it doesn't. Here is the honest comparison.

A bag of ice or a cold towel A cold shower afterwards Cutting your sessions short KOLDWR
Stays in place, hands free No No No Yes
Cooling pack held in place at sauna temps No No No Yes
No drips or mess No No No Yes
Looks normal in a public sauna No No No Yes
Built for repeated use No No No Yes

The Science

Sauna is one of the best longevity habits going. It is just hard on sperm.

In a 2013 study published in Human Reproduction, healthy men using a Finnish sauna twice weekly showed significant reductions in sperm count and motility, with effects lasting weeks after each session. KOLDWR is built to reduce heat exposure in that one area while you take the full session everywhere else.

Read the science

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