Sea To Summit Ember III Down Quilt Review

Last Updated on 16/10/2023

Sea To Summit Ember III Down Quilt Review

In this Sea To Summit Ember III review, I share my experiences so far with this ultralightweight and warm camping quilt. If you are looking for the warmest, most packable, and lightweight alternative to a sleeping bag, you need to check out the Ember series from Sea To Summit.

Sea To Summit Ember III Down Camping Quilt Review

In a hurry? Here’s the short review:

The Ember III down camping quilt from Sea To Summit is unbelievably warm, lightweight, and packable. If saving weight is one of your priorities and you have an insulated sleeping pad, then the Ember quilt is one of the best options for backpacking and thru-hiking. It resembles the Sea To Summit Spark sleeping bag I reviewed here but with no zip or hood.

I tested the Ember III quilt with some other equipment, including the Sea to Summit Ether Lite XT sleeping pad and the Aeros down pillow, both of which offer insulation from below. If I were to use it with an uninsulated air pad and standard air pillow, I am pretty sure I would have felt the cold from the ground more than I did.

Getting in and out of the quilt while it is fastened under the sleeping pad is not quite as easy as with a sleeping bag. It helps to keep the straps loose and then tighten them once you’re in. You can also leave the top one undone if you want, but you shouldn’t have to. You can also get away with using it like a sleeping bag if you pull all the straps as tight as they will go.

The toe box is closed for the first 10 inches or so, which is important to keep your feet warm as they will be the first thing to get cold. It then opens up down the middle at the back and spreads out so that it easily wraps over the sides of your sleeping bag. This gives you lots of space spread out on your back as well as roll over unhindered if you sleep on your side.

Sea to Summit Ember 25-Degree Ultralight Down Backpacking Quilt, Regular


Benefits of the Sea To Summit Ember III Down Quilt

Some of the main reasons to get this camping quilt are:

  • Ultra lightweight
  • Incredibly packable
  • Unbelievably warm
  • Super soft and comfortable material
  • No zips to weigh you down or brush against you on cold nights
  • More space to spread out than a sleeping bag
  • Available in multiple temperature ratings

Downsides of the Sea To Summit Ember III Down Quilt

Some reasons why a camping quilt like this might not work for you:

  • No hood to keep your head warm
  • Not as efficient as a sleeping bag at retaining body heat
  • Requires an insulated sleeping pad in cold weather
  • Climbing in might not be easy for some people

Sea To Summit Ember III Down Quilt features and specs

Features and Specifications

Here are the features of the Sea To Summit Ember III Down Sleeping Quilt:

  • PACK SIZE: 7 x 8 in / 18 x 20 cm / 5.4 Liters
  • WEIGHT: 26 oz / 757 g
  • FILL WEIGHT: 17.6 oz / 500 g
  • SIZE/SHAPE: Regular Mummy
  • INSULATION: Ultra Dry 850 FP Down Insulation
  • MATERIALS: 10D Nylon Shell With 7D liner Fabric
  • Box Baffle Construction
  • Includes four adjustable straps to secure onto a sleeping pad
  • Cushioned internal shoulder-end draw-cord
  • Compatible with Sea To Summit sleeping bags and most sleeping pads

Sea To Summit Ember III temperature rating

Warmth and Temperature Rating

You can get the EMber Quilt in three different temperature ratings, with the III (25F) seen here being rated for below freezing. There is no doubt this will keep you warm from above through most of the year, but in winter, you will need an insulated sleeping pad to keep you warm from below.

Once you’re under your quilt and you give it a few moments, you feel the warm air starting to gather among the down insulation, and it doesn’t take very long at all to warm up. The foot box is as warm as any sleeping bag, and you don’t have to sacrifice any warmth there. However, it doesn’t have the same cozy sleeping bag feeling for the main body.

It still feels warm, but because you have the extra space at the sides, it doesn’t hug you the same way a mummy sleeping bag does. For this reason, I think I’ll be using this well within its temperature range. That being said, I will undoubtedly find its limits this winter so I will keep you updated as this review progresses.

You can also use it as a sleeping bag if you tighten the straps up as tight as they will go. This leaves a small gap of around 4-5 inches, which can be positioned on your side so that you can keep it fairly sealed. It then feels like a sleeping bag with the zip open, except there’s no zip on this quilt.

Sea To Summit Ember III comfort

Comfort and Fit

Comfort-wise, the material is silky smooth and glides across the skin, so it never feels sticky. This makes it extremely comfortable and soft, which is a pleasure to tuck yourself into. The only downside of the quilt design in terms of comfort is that you usually have to lay on a bare sleeping pad, which isn’t as soft and comfortable as the quilt.

You can get the Sea To Summit Ember III Down Quilt in a regular size (as seen in this review), as well as a long version and a double. I would actually recommend everyone just get the long version, which only adds three ounces but means you can pull the quilt right up over your head. The double Ember quilt is ideal for couples as stand-alone bedding or as something to put over the top of both sleeping bags for extra warmth.

You won’t have any issue with the fit, which will cover pretty much all standard to large sleeping pads. It fastens around the back with adjustable buckles, so if you need some extra space inside, you just release some tension on the straps.

Sea to Summit Ember 25-Degree Ultralight Down Backpacking Quilt, Regular

Weight and Pack Size

The weight and pack size of the Sea To Summit Ember III Down Quilt are the main reasons to choose this over the Spark sleeping bag. It weighs a tiny 26 ounces (757 g) and packs into a compact 7 x 8-inch ball, which means it takes up only a fraction of the space as a similar synthetic sleeping bag and weighs about half as much as some of its rivals. Check the image below for a comparison next to a water bottle.


Having such a lightweight and portable sleeping bag means that you can fit all your camping gear inside a small bag and aren’t being weighed down by it all day. The fact that there is no hood and no zip saves a significant amount of weight, but also, there is less overall fill weight and material weight as there is a large section missing off the back.

Overall, I don’t know a more lightweight or compact camp bedding for 25 degrees Fahrenheit temperatures than this quilt.

Sea To Summit Ember III down quilt without hood

Materials and Construction

The materials are of the highest quality, and my quilt came with its own personal certificate to show the test results of the insulation and quality inspection. All the stitches are spaced tightly together, and everything feels held together very well, with no loose threads at all, which is often a sign of a cheaply made product.

The down is RDS certified and treated with a water repellent to make it up to 90% more hydrophobic than untreated down. The outer shell is also treated with a DWR to avoid the main concern of the down getting wet. This means that coming into contact with moisture isn’t the end of the world, and it will dry out quickly whilst still retaining body heat.

Everything about it feels high quality and well-engineered. Take the pull cord at the top, for example. It is made from ultra-soft cord and has dual steel eyelets, which make sure the toggle never snags, and everything works as it should. This level of detail is what puts this above almost everything else out there.

Sea To Summit Ember III down quilt sleeping bag

Compatibility and Attachments

Unless you’ve skipped everything up to this point, you should know by now that you need an insulated sleeping pad for this quilt to work effectively. You should have a look at different R-value ratings and choose a sleeping pad that will keep you warm to a similar temperature as your quilt is designed for. It is compatible with all of Sea To Summit’s sleeping pads as well as most other big names like Thermarest, Nemo, and Exped.

The Ember III Down Quilt comes with a storage sack to protect the down when not in use and a stuff sack for carrying it in a backpack. There are three straps on the back with low-profile buckles that are easy to operate with cold hands and can be adjusted to give the tightness you desire. The neckline has a toggle pull cord so you can tighten it up once you’re in, which helps to trap your body heat.

On the Ember I and Ember II, I believe the foot box is open all the way down, which means you can open it up fully as a quilt. You can also attach two together to make a double, or there is a drawstring at the bottom to close it up like a sleeping bag.

Sea To Summit Ember quilt review

Baffle Design

The baffle design on the Ember down quilt is the same as on the Spark sleeping bags. It encompasses horizontal baffles on the bottom half to maximize warmth to your legs and feet. Then, it has vertical baffles on the top half to prevent the down from shifting to one side as you roll over in the night.

An extra chunky baffle runs along the edges and around the neck, which traps the heat and increases comfort when you tuck it in around a sleeping pad. These large tube baffles also help when you use the quilt as more of a sleeping bag and create a very cozy nest over the top of you.

The baffles are the more desirable boxed design as opposed to sewn-through, which gives the down maximum loft and ability to capture warmth. There isn’t anything I can think of that could be improved with the baffles on this campaign quilt.

Sea To Summit Ember down quilt review

Final Verdict

When combined with an insulated sleeping pad, the Sea To Summit Ember III Down Quilt is the most lightweight and packable sleeping system out there. For ultralightweight backpackers and thru-hikers who count every gram, the Ember quilt is the perfect solution to keep you warm on the trail.

Yes, you need an insulated sleeping pad to pair it with in the colder limits of the quilt and maybe a wooly hat to keep your head warm, but you likely have those items already, so this is making the absolute most of your backpack space and weight you carry.

If you want a down camping quilt for cold weather, then definitely go for the Ember III; otherwise, the Ember II would be my recommendation. The added benefit of being able to open the quilt like a blanket makes it so much more versatile for more than one person. Check them out here:

Sea to Summit Ember 25-Degree Ultralight Down Backpacking Quilt, Regular



I hope you enjoyed this Sea To Summit Ember III Down Quilt Review and found value in it. Let me know what you think of this ultralightweight camping quilt in the comments below.

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This article has been written and/or edited by Andrew N. 20+ years of hiking, mountaineering, and camping experience, with access to all the latest outdoor gear.

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