What it is
Blankets let you adjust warmth night to night, which is easier than switching duvets. Cotton (woven, waffle or knit) is breathable and washable; wool is warm for its weight and handles moisture well; fleece and plush polyester are warm and cheap but trap heat and sweat; 'cooling' blankets use smooth synthetic or lyocell fibres that feel cool to the touch.
Layering is the useful idea for sleep: two light layers you can shed beat one heavy layer you kick off at 3am.
How strong is the evidencenone
There are no trials of blankets and health. Sleep-temperature research shows humid heat under the covers disturbs sleep, which supports breathable layers you can adjust. Beyond that, choose by feel.
The claims you’ll meet2 checked
Cooling blankets lower your body temperatureUnprovenThey feel cool to the touch (sometimes quoted as a 'Q-max' value), but the sensation fades as the fabric warms. There's little sleep data.
Wool regulates temperature for better sleepMixedWool handles moisture well, and small wool-industry-funded studies found wool sleepwear helped slightly, but wool versus polyester bedding made no difference in a lab study.
What to look for4
- ✓Weight and weave for your climate. Open weaves (waffle, cellular) breathe best.
- ✓Machine-washable at the temperature you need.
- ✓A size that covers the bed without dragging on the floor.
- ✓Pilling resistance if you choose fleece or plush.
What to skip2
- ×'Temperature-regulating' claims without data.
- ×Treating organic or fair-trade labels as health features. They're ethical choices, which is a fine reason on its own.
Take care1
- !No loose blankets for babies under 12 months. Use a baby sleeping bag instead.