The Casper Humidity Fighting Duvet is specifically engineered for hot sleepers and those who experience night sweats. The fill is a proprietary blend of eucalyptus-derived lyocell fibre and microfibre that actively wicks moisture away from the body during sleep — rather than just not retaining it passively. The result is a duvet that regulates sleep temperature more actively than any other product in this comparison. The fill is not down, which suits those with down allergies. Lightweight despite its warmth rating. The 100-night trial is adequate for a seasonal assessment.
Available on amazon.co.uk · Prices in GBP. Ships from Amazon.co.uk.
| Fill material | Lyocell + microfibre blend (moisture-wicking) |
| Shell material | 100% lyocell shell |
| Warmth level | All-season (cooler feel than equivalent tog ratings) |
| Construction | Channel-stitch — fill secured in channels |
| Machine washable | Yes — cold, gentle cycle |
| Trial / Warranty | 100 nights / 1 year |
The Casper Humidity Fighting Duvet addresses a specific problem that most duvets do not: active moisture management during the night. Lyocell (Tencel) is derived from eucalyptus cellulose and has a micro-fibril structure with significantly higher moisture-wicking capacity than cotton, polyester, or down. The practical effect is that the Casper duvet absorbs and disperses sweat more quickly than competing products, reducing the humid microclimate that develops under conventional duvets for hot sleepers.
The lyocell shell amplifies this effect — the entire surface in contact with the sleeper wicks and disperses moisture. This dual lyocell construction sets it apart from products that use lyocell fill inside a conventional cotton or microfibre shell. At $189, the justification is the performance advantage for hot sleepers, which is real and consistent.
£159 · Prices in GBP. Ships from Amazon.co.uk.
See how the Humidity Fighting Duvet compares to all 6 models in our full comparison.
Full comparison →