KOLDWR is a cooling boxer brief kit designed to reduce heat exposure where it matters during sauna and heat therapy sessions. The kit includes one pair of boxer briefs with a sewn in front pocket and two reusable gel cooling packs.

Research shows that regular sauna use raises scrotal temperature significantly, which can impair sperm production, motility, and DNA integrity. Your testes need to stay 2 to 3°C below core body temperature for healthy sperm production. KOLDWR is designed to keep them cool while you enjoy the cardiovascular and longevity benefits of heat therapy.

Place both gel packs in the freezer for at least 2 hours. Before your sauna session, slide one into the sewn in front pocket of the boxer briefs. The pack sits against the scrotal area and keeps it cooler through your session.

We have not run a laboratory test of pack duration at sauna temperature, so we do not publish a number. The pack cools hard while it is frozen, and once it thaws it keeps insulating, so the area stays cooler than bare skin for the rest of the session. Two packs ship in the kit, so you can swap a fresh one in for another round.

A sealed, BPA-free, non-toxic cooling gel. The packs are built for repeated freeze-and-use cycles. Do not microwave or puncture them; wipe clean with a damp cloth.

Yes. The boxer briefs are made from 92% modal and 8% elastane, the same performance fabric blend used by major athletic brands. The gel packs are soft and flexible, conforming to your body. Most users report that the initial cool sensation becomes comfortable within the first minute.

We currently offer sizes S through L. The fit is true to size; if you are between sizes, size up. Check the size guide on the product page for measurements.

XL and XXL are not in production yet. Tell us your waist size in the form just below this section and we will let you know when it is.

Absolutely. KOLDWR works for any situation involving prolonged heat exposure: hot yoga, long drives, or just hot climates. Some users wear them during workouts or while working at a desk for extended periods.

No. KOLDWR is a wellness product, not a medical device. It is not intended to diagnose, treat, cure, or prevent any medical condition. If you have concerns about fertility, consult a healthcare professional.

Orders ship as soon as the next production run lands. You will receive an email with tracking information once your order is on its way.

Yes, to some countries. Free shipping within the United States. We also ship to Canada, the UAE, Australia, New Zealand, Switzerland and Singapore at a flat $25 tracked rate, duties paid on delivery. Other countries are not open yet. Join the email list at the bottom of the page and we will tell you when yours is.

Yes. You can cancel for a full refund at any time before your order ships. Just email support@koldwr.com with your order number.

Every order is covered by our 30-day money-back guarantee. Return unworn pairs free within 30 days of delivery for a full refund. See the Refund & Returns Policy for details.

Machine wash the boxer briefs on a cold cycle and hang dry. Remove the gel packs before washing. The gel packs can be wiped clean with a damp cloth. Do not microwave or puncture the gel packs.