Split Blankets, Not Beds
Two bodies, two thermostats, two blankets — the cheapest sleep upgrade a couple can buy.
- Difficulty
- Starter
- Time to result
- ~days to results
- Steps
- 4
- Confidence
- 78%
Gartenberg wrote an article titled 'Split Blankets Not Beds' making the case for a fix so simple it barely registers as an intervention. Temperature is a real lever — cooling the body before bedtime helps you fall asleep, and because you lose thermal regulation during REM, the ambient environment does work your body can't. But couples have genuinely different temperature needs, especially different sexes, since men and women run at different temperatures. A single shared duvet forces one setting on two systems, so someone loses every night. Multiple blankets — normal in European countries like the Netherlands — lets each person tune their own layer while keeping the shared bed intact.
Origin
Gartenberg wrote it up as an article after observing that the Dutch and other European countries already treat separate blankets as the default, while the Anglo world defaults to one shared duvet and quietly tolerates the cost.
Core principles
- 01Cooling the body before bedtime is a cue that helps you fall asleep.
- 02You lose thermal regulation during REM sleep, so ambient temperature matters more than intuition suggests.
- 03Sleep partners genuinely have different temperature needs — men and women run at different temperatures.
- 04A shared blanket forces one thermal compromise on two different systems.
- 05Splitting the blanket solves the conflict without splitting the bed.
How to run it
- 1
Name the mismatch as normal
Recognise that a sleep partner having different temperature needs is normal, especially between different sexes, because men and women run at different temperatures. It's a design problem, not a compatibility problem.
- 2
Split the blanket
Adopt separate blankets — one per sleeper — as is normal in European countries like the Netherlands. Each person then controls their own thermal environment independently.
Pro tip Size each blanket for one person; a shared-size blanket per person just recreates the tug-of-war.
- 3
Set the room cool
Combine the split blankets with the standard quiet, dark and cool environment. The cool room plus a personal blanket gives each sleeper a workable range.
Watch out You lose thermal regulation during REM, so the room can't be left to your body to correct.
- 4
Add a pre-bed cooling cue
Cool your body before bedtime as a cue to help you fall asleep. This can be as simple as ambient cooling, or via devices designed to decrease body temperature.
In the wild
Gartenberg pointed to European countries like the Netherlands, where having multiple blankets on a shared bed is simply normal, in contrast to the single-shared-duvet convention elsewhere.
→ He framed it as an easy way to hack your sleep in terms of getting the right temperature — a fix requiring no technology, only abandoning a convention.
Common mistakes
Splitting the bed instead of the blanket
The title is the argument. Couples who identify a thermal conflict often escalate to separate beds or rooms, when the variable that actually differed was one layer of fabric.
Negotiating one 'fair' temperature
Averaging two genuinely different thermal needs produces a setting that is wrong for both people rather than right for one. The needs aren't a preference to compromise on.
Is it for you?
Best for
Couples sharing a bed with mismatched thermal needs — Gartenberg notes this is especially common with different sexes.
Not ideal for
Solo sleepers, or couples whose sleep disruption is driven by movement or noise rather than temperature.
From the transcript
“There's a lot of studies out there that show cooling your body before bedtime is a nice cue to help you fall asleep.”
“Especially if you have a sleep partner that has different temperature needs, which is normal, especially if it's different sexes because men and women run…”
“So I wrote this article, Split Blankets Not Beds, where we talked about how simply having multiple blankets, which is something that's more normal in…”
From the episode
Daniel Gartenberg: Unlocking the Power of Sleep
Daniel Gartenberg