If you want natural instead of polyester filling, Snuggledown offers you the option to choose a blend of 85% goose feather and 15% goose down. This blend is very warm and you will not be cold in any period of winter. It has an internal box construction, so that the filling always stays in the right place, without any cold spots. We use the Snuggledown Hollowfibre duvet, like any other winter duvet, to keep us warm and comfortable during the long winter nights. We also use it to sleep in an allergen-free environment because it is very dangerous to be exposed to allergens in your sleep, even if you have no history of allergic reactions. So, we use it: Light yet warm and deliciously plump and cosy, there’s a reason this duvet has aced our tests and won the top spot, despite being expensive. It’s made from a high proportion of Hungarian goose down – 90 per cent down to 10 per cent feather – and you can really feel the quality of the down in its cloud-like softness. The down and feathers down are sourced from cruelty-free suppliers as a by-product of the food industry.

Some duvets come in 'four-seasons' or 'all-seasons' sets. With these you get one light duvet (usually about 3.5 tog) and one heavier one (usually about 10.5 tog). The light one will be enough in hot summer months, and the heavy one suits spring and autumn weather. When you need extra warmth in winter, you can combine both. Standard UK duvet sizes The Ultimate Luxury duvet is filled with synthetic material, but unlike our reviewee which is filled with hollowfibre, this one is filled with microfibre. The differences between hollowfibre and microfibre are not major, and this duvet is designed to trap air. Another difference is the cover made of jaquard soft cotton fabric. Features you should know about Snuggledown Scandinavian duvet Other options include silk and linen, but down and feather remain the most popular for their warmth and breathability. Casson herself sleeps with a down duvet from luxury German brand Mühldorfer, “as it’s the lightest and most luxurious.” (Mühldorfer duvets are used in luxury hotels in over 100 countries, which answers the common question, “What duvet do hotels use?”) What tog duvet should I buy?We also looked at tog sizes, fillings, and whether the duvets were machine washable. Here is what we found, starting with our favourite. Don't buy it if: you're on a tight budget as this luxury duvet has a luxury price tag. If you're a hot sleeper or suffer from night sweats then you might find down too warm; opt for a more breathable wool-filled duvet instead to avoid overheating. And, if you're vegan, then the feather and down fill won't be for you. First up, it's synthetic fillings. These duvets are filled with manmade fibres, like polyester and polymide that are made from petroleum-based plastics. The best duvet should keep you cool and comfortable in the summer months and warm in winter. This is called thermoregulation and it’s the key to a good night’s kip.

That said, personally, we think 13.5 tog remains one of the best winter duvet weights, with some finding 15 tog can retain heat a little too much during the night and lead to overheating.

I’d been on the hunt for a light summer duvet for a while when I came across this Silentnight number. I’m the kind of person who would rather sleep under something and be hot than sleep under nothing. Hollowfibre or microfibre polyester duvets are the most popular type among Which? members – nearly half own one of these. Down is really very light,” says Emma Casson of The Bed Expert. “Feather-and-down is cheaper and a bit heavier – and some people like a bit more weight. Then you’ve got your synthetics, like microfibre. You can have really good quality synthetics nowadays. They’re really breathable.”

Don't buy it if: the price makes your eyes water. As well as being the softest duvet fill, down is also the most expensive fill, and 90% Hungarian goose-down is pretty much the best quality you can get. If you're a hot sleeper or suffer from night sweats then you might find down too warm; opt for a more breathable wool-filled duvet instead to avoid overheating. And, if you're vegan, then the feather and down fill won't be for you. Hypoallergenic means that the actual material and filling of the duvet isn't made of a known potential allergen, like feathers or wool. But other allergens, mainly dust mites, can still develop on these types of duvets. Pricing for other destinations within the UK is dependent on weight of parcel and geographical locationCons: Can be expensive, needs to be washed gently at a low temperature, can seem flat in comparison with other fillings The cooling effect definitely works. During a run of hot nights I sweated less, woke up less and slept better. It’s expensive, but I’ve yet to find a comparably cooling duvet. Excludes post codes starting with BFPO, BT, FK, G83, GG, GY, HS, IM, IV, JE, KW, PA(20-78), PH(18-42), ZE Although the Classic Hollowfibre version is also hypoallergenic, the manufacturer has gone a step further with this duvet. Filling is treated in a special way to help reduce the build-up of dust mites and bacteria. It is tested and approved by leading Allergy UK experts. Snuggledown Goose Feather & Down duvet