A white duvet on a bed with two pillows and green wallpaper with a thermometer.

Do TOG ratings tell you how comfortable your duvet will be? 

If you’ve bought a duvet in the past, you’ve probably been told to look at the TOG rating – a specific number that supposedly tells you how warm the duvet will be. But what if we told you that these fixed TOG ratings don’t apply to our wool duvets?

At Devon Duvets, we spent 19 months developing the optimal wool duvet for breathability and body temperature regulation. Unlike synthetic, feather or down-filled duvets, our duvets don’t just trap heat – they adapt to you.

In this blog, we’ll explain why fixed TOG ratings don’t work for our duvets, how wool helps regulate your body temperature naturally, and why this makes all the difference when it comes to a better night’s sleep.

A luxurious lightweight wool duvet with botanic leaves in a bedroom.A luxurious lightweight wool duvet with botanic leaves in a bedroom.

Why fixed TOG ratings don’t work for our wool duvets

TOG ratings were created to measure how well a duvet traps heat…but there’s a problem -TOG tests are conducted in a fixed environment where the temperature never changes.

However, real-life sleep isn’t like that and here’s why:

  • Your bedroom temperature fluctuates overnight. It can drop in the early hours or rise due to central heating.
  • Your body temperature changes while you sleep. As part of your natural sleep cycle, your body warms up and cools down at different stages.

A synthetic, feather or down duvet acts like a thermos flask – it can retain heat, but it can’t adapt when your body needs something different.

That’s why we don’t use fixed TOG ratings for our wool duvets – because these don’t reflect what happens in real-life sleep conditions

A white wool duvet on a bed with a book on the bed in a cosy bedroom.A white wool duvet on a bed with a book on the bed in a cosy bedroom.

What makes a Devon Duvets wool duvet different?

We knew wool had incredible natural properties, but we wanted to perfect it for sleep. That’s why we spent 19 months developing a wool duvet that is not only individually hancrafted but also:

  • Doesn’t trap heat – it regulates it: Wool responds to your body’s needs, keeping you in the ideal temperature zone.
  • Wicks away moisture: Wool absorbs excess humidity and releases it, preventing overheating.
  • Adapts to temperature changes in your bedroom: If your room gets cooler or warmer, the duvet naturally adjusts.

This all adds up to a duvet that can help you to sleep better. Unlike synthetic or down-filled duvets, our wool duvets work with your body – not against it.

A white duvet with pillows and botanic lives in a modern bedroom.A white duvet with pillows and botanic lives in a modern bedroom.

The science behind wool bedding

Research shows that wool bedding helps maintain thermal comfort, leading to deeper, more restful sleep. This includes a study by the International Wool Textile Organisation, which found that wool bedding improves sleep quality by keeping sleepers in a comfortable temperature zone throughout the night. Another study found that people sleeping on wool bedding woke up less often during the night compared to those using synthetic bedding.

These studies confirm what we already know – wool doesn’t need a fixed TOG rating because it naturally adapts to your needs.

Below, we’ve answered some of the most common questions people ask when looking for the best duvet for temperature regulation.

Two white duvets roll up on a bed with the sun shining in.Two white duvets roll up on a bed with the sun shining in.

Commonly asked questions about wool duvets and TOG ratings

1. Do TOG ratings apply to wool duvets?

No, TOG ratings don’t accurately measure wool duvets because they only test how much heat a duvet traps in a fixed environment.

Wool doesn’t just trap heat – it regulates your body temperature. This means a wool duvet will keep you warm when it’s cold and cool when it’s warm, something TOG ratings can’t account for.

That’s why at Devon Duvets, we don’t assign fixed TOG ratings to our wool duvets – they work in a way that TOG simply doesn’t measure. We use fluctuating TOG equivalences to reflect this.

2. Why does my duvet make me sweat at night?

If you find yourself overheating under a duvet, it’s usually because the materials are trapping too much heat. Synthetic, feather and down duvets retain heat like a thermos, making it difficult for your body to cool down when needed. Whereas, wool duvets, like ours, wick away moisture and adjust to your body’s temperature, preventing overheating.

If you struggle with night sweats, switching to a breathable wool duvet can help regulate your temperature and improve your sleep.

3. Are wool duvets warm enough for winter?

Yes! Wool duvets keep you warm in winter because wool is a natural insulator. The key difference is how it retains warmth:

  • Instead of trapping heat like synthetic materials, wool adjusts based on your body’s needs.
  • If you get too warm, it releases excess heat.
  • If the temperature drops, it retains warmth without overheating you.

4. Is a wool duvet better than a feather or down duvet?

It depends on what you’re looking for, but wool duvets have key advantages over feather or down:

  • Feather duvets and down duvets trap heat, making them feel too hot in warmer weather.
  • Wool duvets adapt to body temperature, keeping you comfortable all year round.
  • Wool naturally wicks moisture away, while down can trap humidity, leading to dampness.
  • Wool is naturally resistant to dust mites.
  • Wool is naturally fire retardant.

5. How long do wool duvets last?

A high-quality wool duvet, like those made by Devon Duvets, can last many years with proper care.

  • Wool is naturally resilient, meaning it maintains its loft and shape better than synthetic duvets.
  • It’s naturally antibacterial and hypoallergenic, reducing dust mites and allergens.
  • Unlike synthetic duvets, it doesn’t degrade quickly over time.

For longevity, we recommend airing your duvet regularly and storing it in a breathable cotton bag when not in use.

1. Wool Sleepwear and Sleep Onset:

A study by the University of Sydney found that adults wearing wool sleepwear fell asleep in just 12 minutes, compared to 22 and 27 minutes for those wearing polyester and cotton, respectively. 
woolmark.com

2. Systematic Review on Sleepwear and Bedding Materials:

A systematic review published in the Journal of Sleep Research examined how different sleepwear and bedding materials affect sleep quality, highlighting the advantages of wool in regulating body temperature and improving sleep. 
pubmed.ncbi.nlm.nih.gov

3. Wool Bedding and Sleep Quality:

Research summarized by the International Wool Textile Organisation indicates that wool bedding and sleepwear promote a better night's sleep by regulating body temperature more effectively than other fibers. 
americanwool.org

4. The Science Behind Wool Bedding:

iwto.org/resources/fact-sheets

A wool duvet is a duvet that works with you

If you’ve ever woken up sweating or shivering under a synthetic or down duvet, you’ll know that TOG ratings don’t tell the full story.

A duvet shouldn’t just trap heat – it should work with your body to keep you comfortable all night long.

That’s why we spent 19 months developing the perfect wool duvets at Devon Duvets, to help keep you at the right temperature, no matter the season.

If you have any questions about our award-winning range of 100% British wool duvets, each one individually handcrafted in our Devon workshops, then please get in touch by calling 01752 345399 or contacting us via email. The team are happy to help!

 

Ref: International Wool Textile Organisation