Help & FAQ.

One modal-knit brief with a zip front pocket and padded liner, plus two contoured, reusable gel packs.

The padded front pocket holds a removable cooling pack. The idea draws on Bryan Johnson’s personal experiment using packs between clothing layers.

Arctic Nut’s sauna performance, safe temperature and wear duration have not been established. Johnson’s routine is not an instruction for this brief.

Protection of sperm motility has not been established for this brief. The sauna study and Bryan Johnson’s personal experiment did not test Arctic Nut.

Do not put a frozen pack directly against skin; keep the padded fabric barrier in place. Stop if cooling feels painful or causes numbness or skin changes. Do not use on broken or irritated skin, and do not use cooling to prolong sauna exposure.

If you are trying to conceive or have health concerns, discuss heat exposure with a qualified clinician. A cooling pack is not proof of protection.

Remove the gel packs before washing the brief and follow the garment care label. Wipe the packs clean rather than machine washing them. Do not puncture a pack or use one that is damaged or leaking.

The hat is made from felt cloth, with contrast binding and a hanging loop. The exact fibre composition has not been confirmed. Follow the care guidance supplied with your hat.

The robe is 100% cotton waffle cloth. It has a shawl collar, long sleeves, a matching belt and front pockets, in an adult unisex design.

Use the guide on the individual product page. The brief runs trim; size up if you are between sizes. The robe guide uses approximate body-weight ranges, rather than garment measurements. Contact us if you need help interpreting a guide before ordering.

Our shipping page has the store’s delivery information. Available delivery options and charges are shown during checkout for your address.

Read the current returns policy for eligibility and how to request a return. If you have a question about an order, contact us with your order details.