The coldest night I have spent in a tent in Britain was in July, on a grassy pitch in the Peak District, with a sleeping bag rated far colder than the forecast. The bag was not the problem. The problem was the six millimetres of nothing between my back and the ground. Sleeping mats are the least glamorous item in the pack and the one most likely to decide whether you wake up refreshed or spend the night turning over like a rotisserie chicken. In the UK they have an extra job to do: coping with damp ground, soft and sloping pitches, and the sort of rough, stony spots that quietly ruin things.

Two families of sleeping mat

Almost everything on the shelf falls into two camps, with a third in between. Closed-cell foam mats are a slab of dense foam with no air to lose: cheap, silent and impossible to puncture. Inflatable mats are an air chamber, sometimes with insulation inside, that packs down small and feels like a proper bed. Between them sit self-inflating mats, which are open-cell foam wrapped in a fabric shell with a valve. They puff up partly on their own and you top them up by mouth.

Knowing which one you are looking at matters, because the trade-offs run in opposite directions.

Comfort: what 2am actually feels like

A basic foam mat is one to two centimetres thick and firm. Back sleepers manage fine. Side sleepers usually do not: hips and shoulders dig through, and you wake up with a numb arm and a grudge. What foam does give you is consistency. It never goes soft in the night, never squeaks, and never develops a slow leak that leaves you on the floor at 4am.

Inflatable mats, by contrast, are five to ten centimetres of adjustable cushioning, which is why side sleepers tend to love them. The catch is that firmness becomes a decision. Blow them up rock hard and they feel like a lilo; underinflate them and your hip bottoms out and touches cold ground. The trick is to inflate fully, lie down, then release a little air until your hip sits just above the floor. That is your setting.

Self-inflating mats sit in the middle at around two and a half to four centimetres. Less plush than a good air mat, far more forgiving than bare foam, and they rarely feel unstable.

Weight and packed size

Foam is bulky but light, and it does not care how it is treated. A three-quarter-length closed-cell mat can weigh well under 400g and be strapped to the outside of a pack, leaving your rucksack's interior for everything else. Put your empty pack or spare clothes under your feet and the short length is no hardship at all.

Inflatable mats roll down to about the size of a one-litre bottle and weigh roughly 400–700g depending on warmth and length. Add a pump sack and you are carrying a bit more still. For the same warmth, foam is often the lighter option; it is just three or four times the bulk.

Warmth: R-values and cold ground

Insulation is measured by R-value, where higher numbers mean more resistance to heat loss. Ground steals heat far faster than air does, which is why a mat matters more than most people expect. Rough guidance for UK trips:

• R 1.5–2: mild summer camping in lowland England, festivals, warm nights.
• R 3–4: a sensible three-season baseline for spring to autumn anywhere in the UK.
• R 5 and above: winter, snow, Highland spring trips and anyone who sleeps cold.

R-values add up when you stack mats, which is one of the most useful facts in this article. Closed-cell foam has a fixed R-value and no internal air movement to rob you of warmth, so it performs exactly as advertised, year after year. Inflatables rely on their internal insulation staying put. Blowing one up by mouth pumps warm, damp breath inside, which can reduce performance over time and even freeze in winter. Use a pump sack if you have one, and store the mat unrolled with the valve open at home.

Durability in wet, rough places

Foam wins this one outright. It survives bothy floors, gorse, flint, dog claws, gravel pitches and being sat on while you pull your boots off. It does not absorb water, so a damp tent floor is no drama. It also doubles as a sit mat, a kneeler when you pitch, and a protective layer under an inflatable on stony ground.

Inflatable mats use lightweight fabrics, often 20–40 denier, and punctures happen. Thorns, sharp stones, pine stumps and carelessly stowed tent pegs are the usual culprits. Carry a patch kit and a bit of tape, know where your valve is and treat it gently. Valve failure is the one repair you cannot do in the field, which is worth remembering when you are choosing between two similar mats. If you camp on rough ground often, put a thin foam mat or a decent groundsheet underneath.

Matching the mat to the trip

1. Car camping with a big tent: prioritise comfort. A thick self-inflating or insulated inflatable mat, R 4 or higher, will pay you back every morning.
2. Three-season backpacking in England and Wales: an insulated inflatable around R 3–4, roughly 500g, is the sweet spot.
3. Scottish Highlands in spring or autumn: step up to R 5, and consider a foam mat under the inflatable for warmth and puncture protection.
4. Winter or snow: R 5–7 plus a foam layer. Snow pulls heat out of you relentlessly.
5. Bothies and rough floors: foam, or an inflatable over a thin foam base.
6. Festivals and short summer trips: a cheap closed-cell foam mat is genuinely fine, and you will not cry if it disappears.
7. Duke of Edinburgh and youth expeditions: foam, every time. No valves to break, no punctures to fix, nothing to go wrong at 11pm.

How to choose without overthinking it

Buy the most comfortable mat you are willing to carry, then add a cheap foam mat if you need more warmth, more protection or a backup. For most UK campers, that means an insulated inflatable for the main job and a foam mat for winter, bothies and stony pitches. If you sleep cold, stack them: the combination is warmer than either alone, and the foam quietly protects the expensive one underneath.

Test your setup at home before you trust it. Inflate the mat, lie on it in your sleeping bag on a hard floor, and see how it feels after an hour. Check the size against your tent's footprint and make sure it fits between the poles. A mat that is slightly too long and touches both walls will funnel condensation straight onto your bag. Ten minutes in the hallway beats a miserable night on a hillside.

Photo: Claudio_Scott / Pixabay