For some years now I have been utilising my down gear as a ‘sleep system’. UK manufacturers PHD have now produced their own complete system. This is not cheap but install might appeal to new TGO challengers who have yet to compete their kit (and who have a decent credit card limit).
So, what do I mean by a sleep system?
Simply, I have put together a collection of down clothing that can be doubled up for extra worth under my sleeping bag. My PHD bag is a little old now but is still pretty good down to zero and just below. However, if the night gets very cold I can supplement it. I know always carry a pair of down trousers and down socks. I change into these quite early on. They allow me to move around the tent with down warmth but without having get into my sleeping bag. But when the cold comes I can always keep them on and slip into the bag. I can also wear my down jacket of lightweight down gilet for upper body protection. This is the ‘sleep system’. The first time I came across this name and concept was with Colin Ibbotson who I remember doing this on one of his early TGO Challenges.
The PHD System
The PHD system takes this system a little further, indeed PHD being PHD have covered the idea very comprehensively. The PHD website promotes Sleep System designed for different weather conditions or for differing destinations (links below).
Let’s look at the UK Winter Camp scenario. PHD provide us with two solutions. The first combines jacket, trousers and socks with a sleeping bag and a separate bag liner. The second combines a heavier bag with a liner. These will keep you warm down to -10 which is probably a bit overkill for TGO challenge weather.
A better bet might be the UK 3 Season system. This has 3 options. Option 1 mixes jacket, trousers and socks with a sleeping bag. System 2 looks at a sleeping bag and a liner and a final system adds a liner to the fist system.
These systems and options provide for a very flexible system and, of course, if you are heading into really cold country you will want a system that is designed for these conditions.
For me — thinking about UK backpacking and the TGO challenge — the UK 3 season system (which can go down to -7) is about right.
In all of these systems I would go for the trousers and socks system for the reason I mention above; you can move around the shelter without being having to get in your bag: pure luxury.
Of course, you candy as I did and put together you own system that can work in the way but the PHD site is a pretty useful starting point.