Buyers' Guide - Sleeping Mats

The classic sleeping mat comes in a closed cell foam material. The 'closed cell' bit is important because it prevents the foam from soaking up water like an open cell version commonly known as a sponge. Pluses are that they're relatively cheap, fairly hard to damage, can be carried outside your pack with impunity and are light and compact once rolled up.

The best known is the legendary Karrimat but there are loads of options out there. One effective evolution is the Ridgerest, which uses a rudged construction to trap extra air under the mat and increase comfort and insulation values. The most efficent ones fold into a neat, easily stowable package.

Generally the more insulation you want, the thicker the foam you need. If you're camping on a glacier, you may need two foam mats to keep the cold at bay.

Finally, some users cite the potential to use a closed cell foam matt as a splint if you break a leg or arm - your call....

The best known of these are made by Therm-a-Rest but again there are plenty of other options out there. They consist of a foam core sandwiched inside an outer made of a tough, air and waterproof fabric. They roll up tightly for carrying, but by opening a valve air is free to flow into the inside of the matt and inflate the foam.

The self-inflating bit is sometimes wishful thinking, you often have to blow into the mat to inflate it properly but even the weakest wuss can usually manage it. As with the classic foam mat, warmth is generally down to the thickness of the matt. Simple, the thicker the mat, the more air it traps and the thicker and more effective the insulation layer.

So why are some mats more expensive than others? The top brands use more sophisticated foam inside their mats with holes cut into them to save weight and bulk. They also tend to use lighter, thinner fabrics to cut weight and pack size. That's a two-edge sword as the really light self-inflaters tend to puncture more easily.

Ultra-lightweight self-inflaters pack smaller than normal foam, though they generally weigh more and are best carried inside the pack to reduce the possibility of puncturing.

Speaking of which, make sure your self-inflating pad comes with a puncture repair kit, a self-deflating mat is no fun.

As a generalisation, self-inflaters are more comfortable and significantly warmer than closed-cell foam mats because they trap more air and pressure adjustments allow for comfort tuning.

If you're car camping rather than backpacking, a really fat self-inflater offers amazing comfort, though at a weight you won't want to carry.

Last point, look for a non-slip finish to stop you from sliding down the mat during the night. Not fun.

Made by Exped, down-filled pads are similar to airbeds but contain high loft goose down to prevent air currents from moving heat away from your body, which is why conventional air beds are useless. The end result is, say the makers, a mattress that's three times warmer than any other mat of the same weight.

Users swear by them, though they're not astonishingly light. So what's the catch? Well, a price starting at around £100 means you have to be serious about your sleeping. A dedicated high altitude glacier camper perhaps. OTT for most, but if you must have the most warmth, possibly the way to go.

If you're a serious lightweight freak you can start by using a three-quarter length pad - not something we'd bother with, and it gets sillier from then on. Some technical climbing packs include a bivvy pad, but they're generally thin, minimalist instruments of torment best left to serious lightweight Alpinists and for emergency use.

Then there's the dark side of adventure racing and mountain marathon where people use bubble wrap as a lightweight alternative to a real mat. Fine if you're too knackered to care, we reckon.

Last but definitely not least, at a weight of under 100 grammes, the Balloon Bed is a winner for lightweight obsessives. A lightweight mattress with channels to take long balloon which you simply pop at the end of a happy night's sleep. The balloon bed comes complete with a pump and gives a depth of around 4cm when inflated making it surpringly comfortable.

We've seen one in action on a bivvy and while it looks ridiculous, the thing works. Who needs bubble wrap?

Unless you're a serious weight freak, and maybe even then, self-inflating mats are the obvious solution. The one downside is that they can puncture and in the field repairs can be difficult unless the leak is easy to spot or you carry a bathtub full of water with you.

They're great on glaciers and significantly more comfortable than normal foam mats, particularly the thicker, luxury versions. Foam is bombproof and cheap if you're not worried about comfort, but most users are won over by inflated comfort first time out.

The down-filled pads from Exped have one major drawback, the cost, though we have excellent feedback on their performance. Finally, adventure racers should be looking at the Balloon Bed, it's hard to beat.