Notice the word “system”. No matter what insulation is above you, what you lay on is integral to both warmth and comfort.
Sleeping pads: the aim is to insulate you from the ground. We lose approximately five times more heat to the ground than we do to the air so it is imperative that the sleeping pad is fit for the conditions. It’s also imperative that the sleeping pad is comfortable for you because a bad night’s sleep does not a happy camper make.
The types of sleeping pad boil down to:
- A foam mat. Cheap, waterproof, durable, good insulation, not especially comfortable, bulky but light. Multimat make a good range for different temperatures. The ones with a silver foil coating are especially warm.
- Self inflating mats. Can be heavy depending on make, good for three season camping, pack fairly small, comfortable. Vaude and many other makers produce good self inflating mats. Good for three season use.
- Inflating mats: need to be inflated, lightest sleeping pads available, expensive, very comfortable. As with the self inflating pads there is a risk of puncture. The Thermrest NeoAir is perhaps the best known example of this type. Great for three seasons use. Exped make a down filled mat- depending on the spec they can handle serious low temperatures but are expensive, heavier and bulky. If you are a back sleeper, Klimit make an interesting mat that gets good reviews. I tried one in a shop and found it very comfortable when on my back but not comfortable on my side. The main attraction of the Klimit is the low weight as its a tubular construction with lots of holes with air acting as the insulator.
My preference is for a NeoAir as its both warm and comfortable. In very cold weather I boost it by using a foam mat underneath. There is a low temperature version of the NeoAir but I haven’t used one so can’t comment. The standard NeoAir is good to just below freezing in my experience.
Turning to insulation there are two types; synthetic and down. Synthetic is good when damp, cheaper but heavier than down. It’s bulkier too. Down is my choice of insulation unless I am bivvying or expect prolonged damp conditions because of its warmth to weight ratio and general comfort. Recently, companies have started making hydrophobic down which means the down is treated with a coating (NikWax?) to repellent water. I have no experience of hydrophobic down so can’t comment on it. I do know that wet “normal” down is useless though. That’s why I believe that synthetic insulation still has a role in damp conditions to play despite its extra weight and bulk.
Synthetic or down, a lot of backpackers use a mummy sleeping bag because the cut minimises weight. They work very well, especially if you’re a back sleeper but they can very annoying to get in/out of and they can feel constrictive. I have camped very comfortably in different sleeping bags and can recommend Snugpak for synthetic and Mammut for down.
However, I have moved to using quilts (synthetic or down) because of their versaltilty. They offer a weight reduction and more flexible temperature control as well as more comfort. Elsewhere in my blog you’ll find a more detailed discussion of quilts but, for me, they are they best option. I use Enlightened Equipment (down and synthetic) as well as a Golite synthetic. I’m a side sleeper and quilts are great for side sleepers, they’re so much easier to get into and out of, pack smaller and are lighter.
To summarise: consider how your top insulation works with your sleeping pad. Synthetic insulation is the best choice for wet or prolonged damp conditions but down is much lighter and has a smaller pack size. Quilts offer more flexibility and less weight for the same temperature ranges than traditional sleeping bags. Whether you go for synthetic or down, foam pad or a neoair, quilt or bag the most important things are warmth and comfort; nobody enjoys a shivering (or sweltering) night on an uncomfortable base. After many years of experimenting I’ve settled on using a quilt with a NeoAir pad in a tent while for bivvying I always use synthetic insulation (because it handles the condensation better) coupled with a self inflating mat ( because they tend to have a lower height) so the bivvy is less cramped.