Did you know your sleeping bag is only as good as the mattress you’re lying on? Without something to insulate you from the ground, all the goose down in the world won’t be able to keep you warm on the underside. Choose a mattress based on the temperatures you most often camp in.

Inflation

Foam-filled mats are self-inflating, drawing air in when they are unrolled. Synthetic- and down-filled mats will come with an inflation sack to ensure moisture from your breath doesn’t get inside. Air-filled models are inflated by blowing into them.

Shape and size

Most mats come in short, regular/medium and large. They may be tapered to save weight and bulk and to make it easier to lay two mats side by side. Short tapered models are perfect for summer camping, while winter models should be full length.

Valves

Valves control airflow in and out of the mat. Some mattresses have two valves: one to inflate and the other to deflate.

Fill

What’s inside a mat is the biggest determiner of its R-value. The warmest mattresses have high-density open-cell foam, thermal heat-reflective linings and down or synthetic insulation that slows convective heat loss into the ground. Air-filled mats are less warm, but they’re lighter. 

Storage 

Store the mat in a cool, dry place, unrolled and with the valve open.

Fabrics and finishes

Fabrics are patterned and coated to provide grip so the user doesn’t slide off during the night. They have DWR coatings for water resistance.

Thickness

Generally speaking, the thicker a mattress, the warmer it will be.

R-value

A sleeping mat’s R-value (resistance value) measures its effectiveness at resisting heat loss. The higher the R-value, the warmer the mattress. 

The international standard ASTM F3340-18 ensures all mattresses are tested in the same way to achieve consistent R-values across brands. This helps consumers to compare and judge the warmth of a mattress. 

Here’s a basic guide to mattress R-values: 

R1–R2: For summer use when temperatures are warm day and night

R2–R4: Suitable for three-season use, including when there is a mild ground frost

R4–R6: All-season use, including when there is a heavy ground frost

R6+: Below-freezing air temperatures day and night, with cold to frozen ground

Therm-a-Rest NeoLoft $599.99 (reg)

Car-camping comfort in the backcountry. It has a taper-free design, soft-touch stretch-knit baselayer-like fabric (75D on the bottom, 50D on top), ContourCore Matrix construction for cushioning and support, and heat-reflecting ThermaCapture technology for warmth. Side rails help prevent roll-off, and it has a pump sack and TwinLock valve system for quick inflation and deflation. Dimensions 56x185cm, 11.7cm thick R-value 4.7 Weight 710g. www.ampro.co.nz

Big Agnes Circle Back Insulated $579.99 (reg)

This luxury mat has a removable, machine-washable, soft fabric cover over an inner air bladder to provide warmth and comfort. It uses heat-reflective film insulation and has a single-port, dual-function valve for inflation. Dimensions 64x183cm, 11cm thick R-value 4.7 Weight 964g. www.bigagnes.co.nz

Therm-a-Rest NeoAir XTherm NXT $599.99 (reg) 

One of the highest warmth-to-weight ratio mats available, it uses a Triangular Core Matrix and ThermaCapture technology to trap and reflect radiant heat. It has a durable 70D nylon base and weight-reducing 30D fabric on top, a quick inflation/deflation Winglock valve, and a pump sack and repair kit. Dimensions 51x183cm, 7.62cm thick R-value 7.3 Weight 440g. www.ampro.co.nz

Sea to Summit Ether Light XR Insulated $369.99 (reg)

This is the thickest and warmest mat in the Ultra Light Sea to Summit range due to Thermal Core insulation that includes a heat-reflective film to minimise heat loss. It has durable 30D/40D fabric, a quick-inflation Xpress valve and a pump/stuff sack, a PillowLock system, anti-microbial treatment and includes a repair kit. Dimensions 55x183cm, 10cm thick R-value 4.1 Weight 470g. www.southernapproach.co.nz

Rab Ultrasphere 5 $349.95 (reg)

This ultralight air mat is for fast-paced trips in demanding mountain conditions. It has two layers of TILT (a heat-retaining technology that works like an emergency blanket, reflecting heat back to the body), offset air chambers to trap heat within the construction, an inflation sack and a repair kit. Dimensions 51x183cm, 8cm thick R-value 4.9 Weight 345g. www.outfitters.co.nz 

Therm-a-Rest NeoAir XLite NXT $549.99 (reg)

An all-year ultralight mat with quieter fabrics and durable Triangular Core Matrix construction paired with heat-reflective ThermaCapture technology to minimise convective heat loss and weight. Improved internal construction reduces noise, and a WingLock valve ensures quick inflation and deflation. Dimensions 51x183cm, 7.62cm thick R-value 4.5 Weight 370g. www.ampro.co.nz

Big Agnes Rapide SL Insulated $479.99 (reg)

With dual layers of heat-reflective film insulation, this mat packs down small and offers greater warmth than previous models. It has a supportive I-Beam construction, larger outer chambers to prevent roll-off, anti-microbial treatment, and a cushioned, quilted top in a durable double ripstop fabric. Inflation sack included. Dimensions 51x183cm, 9cm thick R-value 4.8 Weight 510g. www.bigagnes.nz