If you have not experienced the modern world of “active insulation,” it’s more than just marketing hype. It refers to an insulated jacket that maintains air permeability. In other words, it’s breathable. The idea behind active insulation is warmth across a wider spectrum of aerobic activity than a more traditional, less breathable jacket offers. The breathability comes equally from the insulation and the fabric used to make the jacket. The Arc’teryx Proton LT Hoody is a great example. It’s a light and airy insulated jacket that keeps you warm while staying breathable enough to keep you from becoming overheated and sweaty across a wide range of activity. Similar to the Patagonia Nano Air and the Outdoor Research Ascendant, the Arc’teryx Proton LT Hoody is a good compliment to ski touring in cold temps.
The Arc’teryx Proton LT blends an air permeable outer shell and lining with breathable synthetic insulation. The proprietary materials are light, warm and definitely breathable. It has a soft, light and airy feel with a great, natural range of motion.
Adding breathability to a jacket that is inherently designed to keep you warm may sound a little contradictory. But for cold temps and active pursuits like ski touring, breathability actually broadens a jackets usage. Rather than changing layers with every uphill-downhill transition, you can actually often wear the Proton for the up, down and traversing.
Skiing in the Proton LT
The Proton LT is a bit warm for strenuous trail breaking, especially in moderate conditions. But it’s well suited to high alpine touring in cold or windy conditions. It also offers some of the best weather protection of the three jackets I’ve tested (Patagonia Nano Air, OR Ascendant). Wearing it precludes needing a true shell in all but the stormiest of weather, though I still wouldn’t leave home without a shell in my pack.
Fit for the Proton LT is classic Arc’teryx – athletic and trim. And quality is high. Where does the Proton LT Hoody fit into the quiver of ski touring jackets? Well, it simply replaces the traditional puffy jacket. It’s breathability simply extends its comfort zone. It also drops some weight from your load, as you get more warmth for comparable weight than you find in older synthetic insulated jackets. The only downside is a little less wind protection and the need to keep a shell on your packing list.
If you have not upgraded to active (breathable) insulation, now’s the time. I’ve been running the Arc’teryx Proton LT Hoody for a full season. It fits into a week-long of hut trip with no significant adjustment to the layering or packing program. It’s a bit warm for continuous trail breaking, but breathes nicely for the level of effort required on an existing track. The Proton has quickly became my descent layer of choice regardless of whether I wore it on the skin track or not. It’s still plenty warm to keep you comfortable on a lunch stop and offers even more warmth when worn under a shell. It does not replace a serious down jacket for basecamp use, but it will lighten your load for touring and uphill activities. The Proton LT Hoody broadens the role of the lightweight, packable puffy by adding breathability and maintaining a light airy feel with a high level of warmth.
Arc’teryx Proton LT Hoody – $299 – shop for the Arc’teryx Proton LT Hoody and help support Off-Piste Mag