The Marmot Isotherm Hoody provides a decent amount of insulation in a highly breathable construction. This is a great compliment to a technical shell or even as a stand-alone piece on mild and dry days.
Marmot Isotherm Hoody Insulating Mid-Layer Review
Matt’s Specs: Sizing Info
Waterproofing and Breathability: What sets the Marmot Isotherm Hoody apart from other insulating mid-layers is the breathable Polartec Alpha insulation. Polartec Alpha has great warmth to weight ratio, and still provides some decent breathability. Often, insulated jackets don’t feel very breathable so to find one that does is pretty exciting. I still don’t find it quite as good as a technical shell, but it does breathe well for an insulated jacket. Unfortunately the Isotherm isn’t waterproof, so it’s best for dry days, or for under a technical shell.
Warmth: The Marmot Isotherm Hoody offers some moderate warmth. I run pretty warm, and this would be just about perfect under my technical OR Trickshot jacket on really cold days. It would also work pretty well on its own, especially on cooler spring days in the backcountry. Those who run cold may want slightly more insulation on the coldest days, but with a warm base layer underneath I feel most people could use this year round.
Fit: The Marmot Isotherm Hoody fit’s pretty true to size. It does have a regular fit, and it’s not very tailored in the torso. I think for me, I’d size down to the small since I really don’t like excess material in my jacket. If you do size down, you won’t lose any mobility thanks the Angel-Wing Movement articulation, however I did find the shoulders are slightly tighter in the small.
Features: The Marmot Isotherm Hoody is a mix between a softshell and breathable hardshell. It offers a contoured hood, chest pocket, internal mesh pocket, and hand warming pockets. The hem also has a drawcord, and the sleeves have elastic cuffs. The inside of the jacket is lined with a wicking mesh liner.
Bottom Line: The Marmot Isotherm Hoody is a breathable insulated jacket. It would great for those active skiers that want some extra warmth, but don’t want to compromise breathability. The soft-shell and hard-shell combination is a little weird, and the Pertex shell doesn’t feel all that durable.