This down jacket received a Recommended Buy stamp when tested as an option for women by our expert gear reviewer Judy Armstrong

OK, I know this is not women’s specific, but how could I not include a 1000-fill jacket in this test? I had a Small; I would say an XS would be suitable for a size 12 / Medium woman. Sleeves and torso on the Small were roomy, hips were about right, with the elastane binding allowing stretch if necessary. I could layer this over several other garments, which I found useful in summit and rest-stop situations: easy on, then back in the pack. Fit aside, the sensation of immediate warmth is unsurpassed. The 1000-fill is so high-lofting, it puffs up as if a pump has been attached; this is enhanced by wide baffles, which allow the down to expand so quickly.

Read our review of the PHD Sleep Systems here

PHD’s Peter Elliott keeps his technology cards close to his chest so doesn’t give an actual fill weight, but says K Series has ‘a typical operating temperature of –5C’. Weight is kept to a minimum through simple but effective design: elastane at cuffs, hem and open hand pockets, one small internal chest pocket (zipped) and a cosy, chin-height collar – no hood – with chinguard. I had to be careful to keep the highly-lofted lower arms and cuffs away from campsite cooking (food and stove); overall it was a dream to wear.

PHD is the only company in the world using 1000-fillpower down in clothing and sleeping bags for expeditions and mountaineering: rare, indeed, and wonderful.

Reviewed in February 2016