The PHD Sleep System

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.


Ultimate Flexibility

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.

PHD Sleep Systems



  1. David Williamson says:

    Sound’s like a lot of money Andy.Good sleeping bag,sock’s and a Tammy..Bob your Uncle.

  2. I was very pleased with my PHD Wafer Half bag 165g combined with their Wafer Down Shirt 140g in the Pyrenees last summer (I sleep warm BTW) as a version of their ‘sleep system’. Towards mid October I had to supplement them with a light fleece gillet and light trousers which I wore during the day anyway, so no weight penalty, and a merino beanie. As I wore the Wafer Shirt around town and in camp it meant a decent weight saving overall bagwise. I think the half bag/down jacket combo works a treat.

    I checked out the Bargain Box section of the PHD website and picked up their Winter Wafer jacket 270g -5c with hood and Winter Wafer vest 180g -5c for a very good price… The quality is what you’d expect from PHD – meticulous attention to detail and craftsmanship, plus being unbelievably lightweight for the warmth thanks to 95O fill power.

    I spoke with PHD and they gave some great advice as I was interested in adding the Filler Bag, but they suggested the Wafer Trousers instead for my needs to boost my half bag by 10 degrees, with the added benefit of being warm campwear to bum about in, so I went for them too (sleepless nights re. my credit card!). I’ll go for the Wafer down socks for next winter when funds allow.

    Yes, its not cheap, but comparable to premium down gear from other brands. And its not just a sleep system, its clothing for rest stops/campwear/around town so could be less expensive than having a collection of different bags plus jackets etc. plus it (for me anyway) is lighter/less bulky. And it should all last many years.

    As you said Andy, flexibility is the keyword as I reckon this little lot should cover all my needs, maybe swap the Wafer half bag for my warmer summer bag for temperatures towards minus double digits?

    Good gear!

Write in the box and the login details will suddenly appear!