We put the latest 3-season (spring to autumn) sleeping bags to the test and pick out the best. 

From late spring to early autumn in the UK, 3-season sleeping bags are recommended. In general terms, the 3-season rating should cover lower overnight temperatures of 0C to -5C. Some of the bags we’ve tested pledge comfort ratings as low as -12C.

As well as considering the outside night-time temperature on a camping trip, it’s important to take into account your personal comfort levels. We’re all different and some of us are ‘cold sleepers’.

Women are more likely than men to sleep colder at night, largely explained by physiological differences, including, on average, lower muscle mass.

Hormonal fluctuations will also affect women’s core body temperature at different times of the month and through the menopause.

Age makes a difference, too. Both men and women are likely to suffer a decrease in the body’s circulation capacity as we age, as the walls of our blood vessels lose their elasticity.

When blood moves more slowly through the body, our extremities tend to feel the cold more quickly.

So, it’s worth paying close attention to the lower end temperature ratings – sometimes called the ‘comfort limit’ – as a rough guide to temperature performance. Look for zoned areas of warmth, too – in particular the foot box, hips, and hoods with baffles around the shoulder, neck and face.

In this comparative test of the best sleeping bags on the market right now we look at everything to make sure that you have the most informed decision possible when purchasing your next sleeping bag.


Your guide to sleeping bags

  1. Women’s sleeping bag – best buy
  2. TGO recommended – Women’s sleeping bag
  3. Best budget Women’s sleeping bag
  4. Men’s sleeping bag – Best buy
  5. TGO recommended – Men’s sleeping bag
  6. Best budget sleeping bag for men

What makes a good sleeping bag?

1. Insulation

Sleeping bags use either down or synthetic insulation. Down fill is lighter and warmer for its weight and packs smaller, but loses performance when wet.

It comes in different qualities and fill weights, which affects performance and price. Synthetic fill is less compressible for packing but retains performance when wet.

2. Temperature ratings

In addition to the brands’ own temperature usage recommendations, sleeping bags have three tested and certified outside temperature use ratings: Comfort, Comfort Limit and Extreme.

Comfort indicates a temperature where you can expect a good undisturbed sleep; Comfort Limit is as low as you can expect a decent night’s sleep; and Extreme indicates the temperature where the bag should keep you safe but not comfortable enough for a night’s sleep.

3. Construction

A down bag’s performance comes from its ability to allow the fill to ‘loft’ – to expand fully – trapping as much air as possible to retain body heat. Box wall construction aims to maintain an even density of insulation around your body but adds bulk and manufacturing expense; stitch-through construction is lighter and cheaper but allows cold spots.

4. Entry

Sleeping bags’ entry options range from full-length zips to half zips to no zips at all. Longer zips give easier access and let you cool off; shorter zips can get you a smaller pack size; zipless bags can be tricky to get into in small tents.

Main zips should have baffles to prevent heat loss.

5. Hood

Hoods vary greatly in style but can be vital on colder camps. The most basic are lightly insulated with a simple drawstring around your face whilst some are fully insulated and formed to give maximum protection.

6. Shoulder baffle

There is often an internal baffle that can be tightened around your shoulders to trap the warm air inside the bag. Easy adjustment of this feature is important.

7. Sleeping bag Fit

Most bags have a tapered ‘mummy’ shape, being widest at the shoulders and narrowing down to the foot.

Female and male bag designs account for different body shapes, and improves thermal efficiency by removing dead space. The amount of taper varies and can affect user comfort depending on your natural sleep position.

8. Footbox

Good footboxes are shaped to accommodate your feet whilst allowing insulation to fully loft to maintain warmth.

9. Pack size & weight

In the hills a compact, lighter bag will make life easier; for campsite use a heavier, bulkier bag may be less of an issue.

10. Additional sleeping bag features

Some bags have pockets, useful for keeping camera batteries warm or stashing a headtorch where it’s handy.


Best Women’s Sleeping Bags

How we test our sleeping bags for women

Fiona is a size UK10 and 172cm tall. She is a cold sleeper. She walked and wild camped with the bags (and used the same inflatable sleeping mat) in the mountains and glens of the Scottish Highlands.

To test the DWR, she poured on water and applied a little pressure and movement. The product weights are taken from Fiona’s own digital scales.

Mountain Equipment - Helium 600 Women’s

  • Rating: 5/5
  • Price: £280
  • Weight: 1012g (Long)
  • Pros: Warmth, attention to detail, female-specific
  • Cons: Incorrect weight

Materials: 700 fill power 90/10 duck down; shell and lining: 100% recycled 20D nylon | Temperature: ‘Good Night’s Sleep’ temperature -8°C  | Features: women’s Alpine fit with zoned EXL system, slanted box-wall baffles throughout, five-baffle anatomically shaped hood, four-baffle anatomically shaped and offset foot-box, choice of regular left or right zip or left long zip, neck collar with Lode Lock closure, waterproof roll-top stuff sack, storage cube | Sizes: regular (maximum user height 170cm), long (185cm) | Men’s version: yes


Mountain Equipment makes some bold claims for its Helium range of sleeping bags, which includes 250, 400, 600 and 800 fill versions, and bags for men and women.

The brand states: “Efficiently sized, supremely comfortable and low in weight, each Helium bag offers outstanding all-round performance for backpackers.” 

See if I agree with this in my full review here

Rab Women’s Ascent 700

  • Rating: 4/5
  • Price: £270
  • Weight: 1243g
  • Pros: Warmth, attention to detail, female-specific
  • Cons: Weight, stuff sack

Materials: 650 fill power RDS-certified European duck down with Nikwax PFC-free hydrophobic finish; shell: 100% recycled 30D Pertex Quantum with PFC-free durable water repellency; lining: 100% recycled 20D nylon | Temperature: Rab sleep limit: -9C | Features: wide mummy shape, trapezoidal box wall construction, 3D-shaped neck collar, three-quarter long main zip with down-filled baffle, anti-snag zip insert and anti-snag internal zip guard, zipped internal stash pocket, angled foot box, drawcord stuff sack, zipped cotton sack with water-resistant base for home storage | Sizes: regular, 200cm long, user height 170cm maximum | Men’s version: yes


The Rab Women’s Ascent 700 is 15cm shorter than the men’s regular and has a slightly narrower shoulder width and foot area, which gives a small weight saving of 50g. However, the same down fill weight is maintained, even though the total area of the bag is smaller, resulting in a warmer women’s bag overall.

See more of the Rab Women’s Ascent 700 in our full review here

Robens Serac 600

  • Rating: 3/5
  • Price: £276
  • Weight: 1080g
  • Pros: RDS-certified duck down,compressible stuff sack
  • Cons: Warmth, pack size

Materials: 600 fill power RDS-certified duck down 85/15; shell: 20D 400T nylon ripstop; lining: 20D 400T nylon taffeta | Temperature: comfort -7C | Features: mummy shape, face and neck baffle, full-length insulated zip, easy-adjust hood drawcord, loft expander design for increased warmth, shark-fin foot box, compression stuff sack, mesh storage bag | Sizes: short, 200x85x53cm, body length 175cm; other lengths: 195cm | Men’s version: unisex


You know that feeling of getting into a high-quality hotel bed with a light, floaty but warm duvet? Well, the Robens bag is a camper’s version. The inner fabric feels silky although not flimsy, and the RDS-certified down is lightweight and fluffy. 

However, this is not the warmest bag on test, and I wouldn’t want to camp in temperatures much below 0C

See our full review on the Robens Serac 600

PHD M.Degree 400 K custom-made

  • Rating: 4/5
  • Price: £882
  • Weight: 560g (Standard custom-made)
  • Pros: Warmth, custom-fit and custom-made, weight
  • Cons: Price

    Materials: 1000 fill power European goose down; shell and liner: 7X ripstop nylon with DWR | Temperature: comfort -9C | Features: customised to suit customer size and needs; choice of four lengths and four widths; half and full-length zip, right or left, dual-construction design, oval-shaped footbox, various add-on options at extra cost including waterproof footbox/outer shell, stuff bag, mesh storage bag | Size: 16 sizes, depending on requests | Men’s version: unisex


PHD makes all of its products from start to finish in a UK factory. The company sources more than 95% of materials and components within Europe and minimises global transportation. The down is ethically sourced by PHD itself. 

This goes some way to explain the fairly eye-watering price of the M.Degree, but it’s also a fully custom-made bag. 

Our full review on the PHD M.Degree 400 K custom-made can be found here

Alpkit Cloud Peak 300

  • Rating: 3/5
  • Price: £110
  • Weight: 1405g
  • Pros: Price, synthetic fill
  • Cons: Weight, pack size

Materials: 300gsm Thermolite T3E-ML Ecomade fill; outer fabric: 40D nylon 300T ripstop; lining: 20D polyester | Temperature:  Alpkit sleep limit: -4C, comfort 0C, limit: -6C, extreme -20C | Features: synthetic polyester-based insulation using 35% recycled content, outer fabric with PFC-free water repellency, choice of left or right zip, insulated zip baffle, hood with neck baffle and adjuster, compression bag, machine-washable | Size: regular, 165cm to 180cm | Men’s version: unisex


If you are looking for an alternative to goose down (for ethical reasons perhaps), the Alpkit Cloud Peak 300 is a good choice because of the synthetic fill.

The Alpkit polyester-based insulation also goes some way to being eco-friendly with a 35% recycled content. In addition, the outer fabric is treated with a PFC-free water repellency to ensure greater damp resistance.

Other plus points include the roomy width and length, a big hood with cosy neck baffle and a thick zip baffle.

Our full review on the Alpkit Cloud Peak 300 can be found here

The best sleeping bags for men

How we tested the sleeping bags

Peter slept in the bags in the same woodland bothy and using the same sleep mat to achieve some consistency in judging the overall performance. Peter is six feet tall with a 44” chest and comments on fit are based on his sizing.

The bag’s outer shells were tested for water resistance to spills and condensation by applying clean water and light pressure. Weights are from his scales.


Mammut Perform Down Bag

  • Rating: 4/5
  • Price: £355
  • Weight: 1005g
  • Pros: Comfort, performance, price
  • Cons: Centre zip not for everyone, weight

Temperature comfort limit: -7°C | Materials: 700 fill power ethically certificated duck down, polyester/nylon lining, nylon outer | Features: box wall construction, mummy shape, full-length two way centre zip, shoulder baffle, internal pocket, stuff and storage sacks. Comes with ear plugs and sleep mask. | Size: long | Women’s version: unisex


The Mammut Perform takes a different approach to the other bags in the review with a full-length centre zip for access.

I like the options this entry format presents to you; it’s a feature that can make a real difference to camp convenience, such as allowing you to swap ends in a tent without your zip now inconveniently facing away from the door if you find you’ve pitched on a slope, as well as easily sitting up without leaving the warmth of the bag

See our full review on the Mammut Perform Down Bag here

Mountain Equipment Firelite

  • Rating: 4/5
  • Price: £500
  • Weight: 764g (Regular)
  • Pros: Weight, comfort, performance
  • Cons: Price

Materials: 900 fill power ethically certificated goose down, nylon shell | Temperature comfort limit: -8°C | Features: slant box wall construction, mummy shape, stretch seams, full-length two-way zip, shoulder baffle, stuff sack and storage sack | Sizes: regular, long | Women’s version: yes


The Firelite is the lightest bag in the review but it maintains performance at that low weight by using very high-quality down and a very light shell fabric.

When unpacked the bag lofts very well and once inside the feedback against bare skin is very fast.
The shape is a relaxed mummy with quite a neat upper body and good room for your feet. 

See our full review on the Firelite here

Marmot Helium

  • Rating: 3/5
  • Price: £375
  • Weight: 958g (Regular)
  • Pros: Comfort, price
  • Cons: No shoulder baffle

Materials: 800+ fill power ethically certificated goose down, Pertex Quantum 20D 100% nylon ripstop | Temperature comfort limit: -12°C | Features: box wall construction, mummy shape, full length two way zip, internal pocket, stuff sack, storage sack | Sizes: regular, long | Women’s version: Xenon


As is the case across the bags in the review the Helium comes with certified down fill to guarantee an ethical origin; but additionally the shell fabric of the Helium is made from 100% recycled fabrics.

The bag lofts well and quickly when unpacked, and there is a very quick feeling of feedback – warmth from the bag – against bare skin when you climb in.

The Helium is quite a neat fit but doesn’t feel restrictive, and I found enough leg and arm movement to keep comfortable. 

See more on the Marmot Helium here

Rab Neutrino 600

  • Rating: 4/5
  • Price: £440
  • Weight: 1020g (Regular)
  • Pros: Comfort, performance
  • Cons: Weight

Materials: 800 fill hydrophobic, ethically certificated down; Pertex Quantum outer, nylon inner | Temperature comfort limit: -12°C | Features: box wall construction, mummy shape, shoulder baffle, full-length two-way zip, internal pocket, stuff sack, storage sack | Sizes: regular, long, wide, long wide | Women’s version: yes


The Neutrino has joint lowest temperature rating in the review with a comfort limit of -12°C, making it a bag you can use into winter in the right conditions.

With that performance comes a wee bit of extra weight but there are features and comfort to match. The shape is tapered mummy with a wide upper body that only tapers slightly to my knees then cuts in closer to my feet.

This is very comfortable to sleep in with very natural limb movement possible, but still with a well-shaped and non-restrictive footbox.

The hood is average size for the group in this review and is internally adjustable separately for above-
and below-the-face opening. 

See more on the RAB Neutrino here

Thermarest Parsec

  • Rating: 4/5
  • Price: £360
  • Weight: 906g (Long)
  • Pros: Comfort, performance, price
  • Cons: Top bag design not for everyone

Materials: 800 fill power hydrophobic, ethically certificated down, nylon shell | Temperature comfort limit: -6°C | Features: box wall construction, mummy shape, top bag design, shoulder baffle, full-length two-way zip, external pocket, stuff sack, storage sack | Sizes: small, regular, long | Women’s version: unisex


The Parsec has a different construction format from the other bags in the review and consequently requires a different approach from the user.

The Parsec is a ‘top bag’, which means that the hood, the footbox and the rest of the bag from the ground up is a regular sleeping bag but the back – the area that touches the ground – has very little or no insulation at all.

Our full review on the parsec can be found here