Layering System for 6000m Peaks

Himalayan weather swings from blazing sun to blizzard in an hour, and you generate furnace heat uphill and almost none standing at a belay. A layering system lets you regulate across that entire range. Build it right and you barely think about it; build it wrong and you suffer every day.

The Four Layers

Every Himalayan kit has four layers: base (moisture management), mid (insulation), shell (wind and water), and summit suit (extreme cold). You wear different combinations at different times — the skill is anticipating changes before you sweat or chill.

Base Layer: Merino

Merino wool, 150–200gsm, top and bottoms. It manages moisture, resists odour over weeks, and insulates when damp. Bring two sets: one for trekking, one kept dry for summit day. Avoid cotton entirely — cotton kills, and at altitude that is nearly literal.

Mid Layer: Insulation

A synthetic insulated jacket (60–100g fill) for active use plus a down jacket (180–250g fill) for stops and camps. Synthetic keeps working when damp from sweat; down gives unmatched warmth per gram when dry. Fleece (Polartec 100–200) is a cheap, durable alternative for the trek in.

Shell: Gore-Tex With Pit Zips

Jacket and full-zip trousers in a waterproof-breathable membrane with pit zips and thigh vents. You will wear the shell more than any other layer — buy the best you can afford and make sure it fits over everything else. Test the zips with gloves on.

Summit Suit

For summit days above 6,000m, a one-piece down suit rated to –40°C worn over base layers replaces the mid-plus-shell stack: simpler, warmer, faster at 3am. Bib-style suits allow toilet breaks without full removal. See our gear guide and boot guide for the complete system.