HeatShield™ Fertility Protection Cooling Shorts

Yes. Bryan Johnson shared his personal cooling results: +57% healthy moving sperm, +26% sperm count, and +15% normal sperm shape after 27 sauna sessions with cooling. Garolla et al. (2013, Human Reproduction) showed that regular sauna use cut sperm count and movement by more than half, and that stopping heat exposure let them recover. We built HeatShield from these findings. We say "published data," not "clinically proven," because Johnson's results are from one person, not a controlled study. But the direction is the same across every source we've found.

Most cooling underwear is made for everyday use, sitting at a desk, after a workout. Snowballs says right on their website: avoid saunas. HeatShield is 100% cotton, so there are no synthetics that could shed microplastics in high heat. The gel packs hold their cooling for a full 20–30 minute session at 200°F/93°C. This isn't general-purpose cooling underwear. It's built for the sauna.

The gel pack stays cold for a typical 20–30 minute session. After it warms up, the cotton still keeps a layer between your skin and the bench heat. Each pair comes with 2 packs, so you can swap in a fresh one if you go longer.

They look like normal black boxer briefs. The pouch sits flat in front. Several customers say they've worn them in public saunas with no one noticing, unless they brought it up themselves.

DIY methods work, but they're a hassle every time. Ice melts fast. Towels get soggy. Loose packs move around. HeatShield has a zippered pouch that holds the gel pack in place for the full session. Same idea, just built to remove the friction.

60-day money-back guarantee. Wear them in the sauna. If you're not happy, send them back for a full refund. No questions asked.

Freeze the gel pack for at least 2 hours. Zip it into the front pouch. Put on the shorts. Sauna. That's it.

Yes. We ship worldwide. Orders go out within 3 business days. Delivery usually takes 8–15 business days depending on where you are.