Outlast Summer

During the development of our exceptional 'Gold range' quilts, we realised that technology would allow us to go even further when considering dynamic thermo regulation. Could we obtain the thermo regulating performance of a natural fill duvet in a synthetic?

Thanks to NASA and Outlast® we were able to do so.

Outlast® is a thermo regulating fabric that absorbs heat to keep you cool, and then dissipates what it has stored should the temperature fall. The fabric is made of a web of hexagonal cells that function to maintain a median body temperature for the user throughout the night. Outlast reduces fluctuations in temperature, keeping you neither too hot nor too cold. 

It is a true development of Sleep Engineering that we are delighted to present. It genuinely assists in addressing one of the principle issues of achieving good sleep. Your duvet becomes dynamic, reacting to the actual body temperature of the person using it. It is a fantastic solution for partners who are aware of their differing body heats and differing temperature preferences when sleeping under the same shared duvet. 

We have combined Outlast® with the Lyocell and Quadfil Hollowfibre fills of our synthetic range, and wrapped it in our exclusive 100% Lyocell Gold Outer Cover for maximum moisture dissipation and a sublime feel. In our opinion, this is the ultimate product that combines the Sleep Engineering philosophy of luxury, performance, and technology. 



Sleeping with 'Outlast Summer'

Embodied in our Outlast quilts are a variety of technologies and performance materials:
Highly insulating, highest grade Synthetic hollowfibres.
The botanical fibre, Lyocell, used as a filling for a silken drape, and moisture wicking capacity.
A 100% Lyocell Gold outer cover that is kind to your skin, and improves moisture reduction.
Finally, the inner lining of our Outlast fabric that directly regulates your body temperature.
We offer the Outlast series in two variants. The 'All Seasons' model and the 'Summer'. Both are appropriate for year round use, depending on your bedroom climate and personal preference. If you are aware that in winter you appreciate additional warmth in bed, and in the summer time rarely complain of being too hot, then we recommend the All Seasons, heavier version. If however, you consistently find that you overheat in bed, go for the 'Outlast Summer'. As synthetics, both options are perfect for those that wish to keep a hygienic bedroom environment, and regularly wash their duvet. These advanced duvets are designed to react to you, and do a specific job. Keep you warm in the cold, and cool in the heat. Assisting your overall sleep experience. With your temperature regulated, it is one less thing to be an issue that affects your sleep.

The detail

Filling: 70% Lyocell Fibres
30% Polyester Quadfil Hollowfibre
Outer Casing: 100 % Lyocell Gold + Inner Lining 100% Outlast Fabric (facing side only)
Washable at 60 Degrees and machine dryable.
Made in the European Union
All products are Oeko Tex 100 Certified
Available in Single, King Size, and Super King. Alternative standard or bespoke sizings available on request.

hollow fibre

Synthetic hollow fibres are excellent insulators. Designed to trap warm air within their core, they are soft, flexible fibres that deliver the added benefit of being easily washable, and therefore hygienic.
Not all hollow fibres are created equal, and there are substantial differences in the feel and performance depending on quality. Further innovations such as additional holes to the fibre itself can improve airflow, and therefore the ability to trap air. We use the highest quality hollowfibres available to ensure that both performance and luxury are perfectly combined within our quilts. Hollowfibre is a great choice for those that wish for a performance duvet that it is truly hypoallergenic, and can be regularly washed.


Lyocell is a botanic fibre derived from tree pulp. We use it because it has 50% more moisture absorption than cotton. It is moisture and humidity that are the principle factors in temperature control, hence Lyocell takes moisture away from you keeping you both dry and cool. In its finest forms, Lyocell is produced with a truly silken feel. This is because under a microscope, Lyocell fibres are completely smooth, unlike Cotton. It has a luxurious, beautiful, smooth finish that is kind to your skin, and yet is also completely washable. Our unique 100% Lyocell Gold quilt covers are a true pleasure with advanced performance.

outlast temp regulating

Outlast is patented 'Certified Space Technology™'. It utilises encapsulated 'Thermolecules' to absorb your body heat, in what is a known as 'phase change material'. In doing so, it reduces your bodies natural response to heat - to sweat, and rather than wicking it away, it takes heat away from the skin surface to address sweating and therefore moisture build up before it occurs. Thereafter, the phase change thermolecues release the heat when your body temperature drops. The result is less sweating, less moisture, and a smoothed median night time temperature, that adapts to the individual underneath it. A true Sleep Engineering solution that we are delighted to present in our most premium quilts.

summer soft

Sleep Engineering doesn't have to be overly technical. When considering our quilt ranges, standard UK 'tog' measures are largely inappopriate as most of our quilts are temperature regulating and therefore can not be classified with 'tog'. Our quilts react to you and your body temperature. So we try and keep things simple. Summer soft means that the quilt is lightweight and suitable for those that sleep in consistent temperature environments year round (i.e you use the heating in the winter). Our 'winter warmth' ranges are heavier, warmer, and suitable for the coldest months, and anyone who would naturally say that they require a high level of warmth from their quilt. In practice, the choise is easy and self evident, particulary in person at the Rested Experience.

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