POLYGON HELIOS Insulated Jacket: Designed for Harsh Winter

Outer Jacket That Stays Warm Even When Wet

Snow, ice, and spindrift make winter climbing a constant battle against wetness and cold.

We asked ourselves: Can we create an insulated outer jacket that performs not only while moving, but also during still moments like belaying, setting up camp, or waiting in freezing air?

That question led to the creation of Polygon Helios, an insulated outer jacket designed specifically for winter mountaineering.

This is the story of its development, a pursuit of warmth and functionality built to withstand the harshest alpine conditions.

Insulation That Withstands the Wet

In 2013, we developed our original sheet-type insulation, FINEPOLYGON®. Its greatest strength lies in its ability to retain loft and trap warmth even when wet. Unlike down or conventional synthetic fills that collapse or clump after absorbing moisture, FINEPOLYGON® maintains its structure, continuing to insulate effectively.

Because it does not shed fibers, FINEPOLYGON® can be paired with open-weave outer fabrics that enhance breathability, something that is nearly impossible with down. This versatility has made it a key material in many of our technical mid layers designed for high-output, active use.

However, in winter mountaineering, the greatest need for warmth often comes not during movement but during stillness—while belaying, setting up camp, or resting in freezing air. In these moments, continuous snowfall, spindrift, and sub-zero temperatures create a constant threat of wetness and chill.

To protect the body in such harsh alpine conditions, we set out to create an insulated outer jacket that could perform like a belay parka while maintaining the mobility and durability required for mountain use.

Designed Specifically for Winter Mountaineering

Polygon Helios was built from the ground up for snow and alpine environments.

We selected a lightweight nylon fabric with a DWR finish on both the outer and inner surfaces, allowing it to shed snow even when worn over a hard shell. The fabric also has stretch, ensuring freedom of movement while climbing or setting up camp.

Inside, two to three layers of FINEPOLYGON® insulation are quilted and strategically overlapped in key areas to provide extra loft and warmth where it is needed most.

For the front zipper, we chose a No. 5 VISLON® zipper that resists freezing in sub-zero temperatures and can be opened from both the top and bottom. The cuffs are cut wide for quick layering and can be adjusted with tabs, allowing easy on and off even over gloves or a shell. We also added large zipper pull loops for smooth operation while wearing gloves.

Storage was another key consideration. Along with hand warmer and chest pockets, the jacket features two large inner mesh pockets for stowing gloves or other essentials. Every detail was refined to make it practical and dependable for use in deep winter conditions.

Pack it into the included stuff sack and take it wherever your winter adventures lead.

This is insulation you can trust when warmth matters most.