Sigma Trousers

Warm trousers filled with synthetic insulation for camping in cool and wet conditions. Now also available in custom sizes.
Typical Operating Temperature
Guideline minimum temperature. Sleeping Bag TOT: you should get a night’s sleep, under normal circumstances. Clothing TOT: you should feel warm enough, assuming low/moderate activity. Sleep System TOT: relates to full system. For more details, see our Technical Briefing.
-5°C / 23°F
For clothing, weight is for size: M. For sleeping bags, weight changes with selected length/width. N.B. there may be some variation in the weights of finished products.
220g / 8oz
Sigma Primaloft Insulated Trousers / Pants
My cold weather 'gear of the year' ... insanely warm ... Serious clobber for serious conditions. I am genuinely impressed
Outdoor Enthusiast Magazine.


  • Primaloft Gold® synthetic insulation (60gsm warmth)
  • Breathable & windproof MX outer and inner fabric
  • Edge-stitched for maximum loft
  • Adjustable shock cord at waist
  • Inner security pocket
  • Elasticated ankle
  • Colour: Black
  • Packed size in supplied stuff sac: 13 x 21cm*

*Please note: we make our stuff sacs big enough to allow fairly easy stuffing rather than reducing the gear to the tightest minimum.


Also available in custom sizes. We make clothing to order, so if you’re not a standard size we can make it to fit. To order a non-standard custom size, select the Custom Sizing tab and choose the waist and inside leg sizes that work for you. A custom size takes us a little longer (typically two weeks longer) to make and, because it’s personalized, it’s non-returnable and our customer loyalty scheme can’t be applied.

With a combination of synthetic insulation (Primaloft Gold®), our lightweight MX fabric, and a light and simple design, these synthetic-filled trousers are the perfect choice when it's going to be cold and damp.

In our experience the Primaloft Gold® synthetic insulation absorbs water much more slowly than other synthetic waddings, a marked advantage in cold, wet conditions.

Superlight MX fabric (weight: 32 gsm)

A mini-ripstop nylon with excellent tear strength, MX is the pick of the superfine 15 denier downproof materials. We have tested lighter fabrics, but most have had significant drawbacks, while our confidence in MX is based on several years of extensive use in both our ultralight and our high mountain gear.

Primaloft Gold®

Primaloft Gold® is the ideal microfibre insulation. Ultrafine fibres produce an insulating core that is incredibly soft, lightweight and water resistant. In our experience it absorbs water much more slowly than other waddings, a marked advantage in wet-cold conditions.

The nearest of the synthetics to the feel of down, yet tougher than you would expect. Primaloft Gold® offers the best warmth/weight performance in the Primaloft range

"I put them on and instantly felt the warmth they provide. They seem so brilliantly designed and manufactured. One of the reasons I keep coming back to PHD gear is that I know it's made in the UK and that it's made exceptionally well."
Rob Stretch

"Probably my cold weather 'gear of the year', if you pair these insulated trousers with ... a winter jacket ... you'll be set up for whatever the season ahead throws at you. I have insulated alpine pants that are 3 times the weight and less warm than these. For me, synthetic insulation is a better choice than down in more cold weather conditions, as they are much more likely to get damp at the knees, seat and ankles. These are insanely warm, disperse moisture rapidly and scrunch down tiny. Serious clobber for serious conditions. I am genuinely impressed."
Outdoor Enthusiast Magazine.

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