Sleep systems

Alps Winter: System 2

The Yukon jacket and Alpine Ultra halfbag are ideal lightweight bivvy gear if you want insurance on a climb. Back in camp they can be worn inside the Hispar 500 to boost its performance from -15°C right up to -30°C when you need it. Whatever the weather, you'll still sleep warm.
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.
-30°C / -22°F
Schematic representation of Sleep System. Actual components differ.


  • System Products:
    • Main Sleeping Bag: Hispar 500 (Sleep Rating: -15°C / 5°F) Weight 915g/32oz.
    • Plus Items:
      • Yukon Down Jacket
      • Alpine Ultra Halfbag
  • Full System Sleep Rating: -30°C (-22°F)


The Hispar 500 bag by itself is rated at -15°C, warm enough for valley camps through most of an Alpine winter. When the temperature drops even further, use the jacket and halfbag inside the Hispar bag and boost the performance rating all the way to -30°C. 

On the mountain the Yukon jacket is rated to -15°C and combines with the halfbag for a bivvy at about -7°C. But if you’re serious about sleeping on your route, better take the Hispar bag with you – it weighs less than a kilo and offers a lot of warmth.

K SeriesThe Hispar 500K Sleeping Bag is available in the K Series: performance is the same, but the exceptional loft of 1000 down reduces the weight of the bag to an amazing 770g (27.1oz).

Review relates to Hispar 500 Down Sleeping Bag

"The lightest bag tested yet warmer than some ... The Hispar 500 really does deserve the description 'Ultralight' ... The loft really is astonishing for such a lightweight bag ... the Hispar 500 is my favourite of the bags tested."
Chris Townsend, Winter Down Sleeping Bags test, TGO Magazine.

Review relates to Yukon Down Jacket

"Many thanks for the jacket that you supplied me for the Yukon Arctic Ultra. [It] performed perfectly in temperatures down to -35°C. The light weight and small size was also a huge help and helped me gain second place in the race. I ... am now the second fastest person over the course and the fastest European."
Dr Stuart Gillet (wearing a prototype Yukon jacket).

Review relates to Alpine Ultra Halfbag

"The Alpine ultra half bag has been excellent. I'm a great fan of the anorak/half bag combination and have used it for many years – warm enough most of the time in this country (UK). The system is ideal if you tend to fidget about in the night and find sleeping bag entry + zips + keeping tabs on the dog all a faff particularly when it’s wet and easy to get the inside of larger sleeping bags damp."
Mick Roffe.

Sleep system components

Works well with
From £828.00 915g -15℃
Mountain lightweight for cold conditions. Ideal for fast ascents and quick travel.
From £315.00 250g 3℃
Our Alpine half bag (pied d'elephant) to insulate legs and feet. Camp down to 3°C and bivvy down to -10°C (with a suitably warm jacket)