Short answer: for most people with cold feet, alpaca is the best wool for bed socks. It's warm for its weight, soft, contains no lanolin, and copes with the damp that builds up under a duvet. Choose a soft top that doesn't dig in. If you sleep hot, merino is the better choice. If softness matters more than warmth, cashmere.
Wearing socks in bed divides households. The science is on the side of the sock-wearers, with a few sensible caveats.
Why warm feet help you fall asleep
To fall asleep, your body needs to shed a little core heat, and it does much of this through the hands and feet. In a study published in Nature, the degree to which blood vessels in the hands and feet dilated was the best physiological predictor of how quickly people fell asleep.1
Cold feet work against this. The vessels narrow to conserve heat, and sleep takes longer to arrive. Warming the feet helps them open.
What the bed-sock study found
A 2018 study tested this directly. Six young men slept in a cool room (around 23°C) on two nights, once in bed socks and once without. With socks they fell asleep about 7.5 minutes faster, slept around 32 minutes longer and woke fewer times, with no rise in core body temperature.2
It's a small study, in young men, over single nights. Encouraging rather than conclusive. But it's a cheap, low-risk thing to try.
What makes a good bed sock
- A breathable natural fibre. Feet sweat, even at night. Wool and alpaca manage moisture far better than cotton or fleecy synthetics, which feel warm at first and clammy by 3am.
- A soft, non-restrictive top. A bed sock should never leave a mark on your leg. The point is to let blood reach the feet.
- Warm, not thick. Bulk isn't warmth. Overheating defeats the point, because the body needs to lose some heat to drop off.
- Clean each night. A fresh pair, not the day's socks.
Is alpaca the best wool for sleep?
For cold feet, we think so. The honest comparison:
| Alpaca | Merino | Cashmere | |
|---|---|---|---|
| Warmth | Highest for the weight | Moderate, regulates well | Good, light |
| Softness | Very soft | Soft | Softest |
| Itch | No lanolin, rarely itchy | Rarely, if fine | Not itchy |
| Durability | Good in a blend | Good | Delicate |
| Best for | Cold feet, cold bedrooms | Warm sleepers | Pure comfort, gifts |
Alpaca wins on warmth. The partly hollow fibre traps air without bulk, and with no lanolin it suits people who find sheep's wool itchy.
Merino is better if you start cold and end up too warm. It lets heat go once your feet have warmed up.
Cashmere is the softest thing you can put on a foot. Less warm than alpaca for the weight and more delicate, which matters less in bed than in a boot. See our alpaca vs cashmere comparison.
Which bed socks to buy
Noble doesn't make a dedicated bed sock. Two of ours work well, and our sister brand makes the proper thing:
- Noble Alpaca Crew Socks. Our warmest option for a cold bedroom. Size up if you like a looser fit at night. Black or grey, so nobody knows how long you've been wearing them round the house.
- Noble Merino Everyday Crew Sock. Lighter and very breathable, for people who run warm but still get cold feet.
- The Clare alpaca bed sock from The Cambridge Sock Company. British-made, loose-topped, built for bed. Or their Cam cashmere bed sock if softness is the priority. Full range: Cambridge bed socks.
Other things that help cold feet at night
- Put socks on 20 minutes before bed, not once you're already cold.
- A warm (not hot) bath or foot soak before bed does a similar job.
- Keep a spare pair by the bed. Damp socks are worse than none.
- If you wake with sweaty feet, try a thinner sock, or none.
When bed socks aren't a good idea
- If you have diabetes, reduced sensation or poor circulation in your feet, check with your GP or podiatrist before wearing socks overnight, and never use hot water bottles or heat pads against your feet.
- If your feet are persistently cold, pale or blue, or change colour in the cold, that can be a sign of a circulation problem such as Raynaud's rather than a sock problem. Worth mentioning to your GP. More in Socks for Poor Circulation.
Frequently asked questions
Are alpaca socks good for sleeping in?
Yes. Alpaca is warm for its weight, soft, lanolin-free and manages moisture, which makes it one of the best fibres for bed socks, especially for cold feet.
Is it good to sleep in socks?
For most people, yes. Warm feet help the body shed heat and can help you fall asleep sooner. Choose clean, breathable socks with a top that doesn't dig in.
Alpaca or cashmere bed socks?
Alpaca if warmth is the priority. Cashmere if softness is. Cashmere is more delicate and costs more.
Alpaca or merino for sleep?
Alpaca for cold feet and cold bedrooms. Merino if you tend to overheat at night.
Why do my feet get cold in bed?
Usually because blood vessels in the feet narrow when you're cold, and a cool bedroom keeps them that way. Warming the feet before bed helps. If it's persistent, or comes with numbness or colour changes, speak to your GP.
Should bed socks be tight?
No. A soft, non-restrictive top is better, because the aim is to let warm blood reach the feet.
Shop Noble alpaca socks · Shop The Clare alpaca bed sock
SOURCES
- Kräuchi et al. (1999), Warm feet promote the rapid onset of sleep, Nature — nature.com/articles/43366
- Ko & Lee (2018), Effects of feet warming using bed socks on sleep quality and thermoregulatory responses in a cool environment, Journal of Physiological Anthropology — link.springer.com/content/pdf/10.1186/s40101-018-0172-z.pdf
