What temperature should you sleep at? Cooler than you think
You set the heating to 21 °C because that feels comfortable. In a living room it is. In a bedroom it is two degrees too many — and those two degrees are costing you part of your night.
Sleeping temperature is not a matter of preference. It is a physiological mechanism, and it works the opposite way to intuition.
To fall asleep, your body has to cool down
Your core temperature is not stable across twenty-four hours. It peaks in the late afternoon, then drops by roughly one degree over the course of the evening. It reaches its lowest point in the middle of the night, around four or five in the morning, before climbing again towards dawn.
That drop does not accompany falling asleep: it triggers it. It is one of the internal signals that allows the switch into sleep to happen.
Hence the consequence, counter-intuitive but unforgiving: if your body cannot shed its heat, the signal never fires. You lie awake in a comfortable bed wondering why.
The range: 16 to 19 °C
Recommendations converge on 16 to 19 °C for the bedroom, with the optimum often placed around 18 °C.
That is noticeably cooler than most people will accept. And that is precisely the mistake: a bedroom at 21 or 22 °C feels pleasant at bedtime, when you are still dressed and standing up. Once you are under the duvet, it prevents heat loss for eight hours.
How the room feels at the moment you get into bed is a poor guide. What matters is what the room allows during the night.
The cold feet paradox
This is where the mechanism gets interesting.
Your body does not shed heat evenly. It releases it mainly through the extremities — hands and feet — where blood vessels dilate as you fall asleep to let heat escape outwards. This is peripheral vasodilation.
If your feet are cold, those vessels stay constricted. The heat does not leave. The core does not cool. The signal never fires.
Which produces a result that sounds absurd: warming your feet helps your body cool down. Thin socks, or a warm foot bath before bed, speed up sleep onset in people with cold extremities. It is not a contradiction — it is the same mechanism seen from the other end.
It is not the room warming you up, it is your bed
Plenty of people turn the heating down, find they are still sweating, and conclude that temperature has nothing to do with it.
It has a great deal to do with it — but the room is only half the problem. Between you and the bedroom air sit several layers which let nothing through.
The memory foam mattress is the first culprit. Conventional viscoelastic foam is a thermal barrier: it moulds to the body, increases the contact area, and stores heat rather than dispersing it. You sleep inside a warm imprint.
The pillow concentrates the problem on the most sensitive area. The head releases a meaningful share of body heat, and a solid foam pillow blocks exactly that route.
The duvet is often over-specified. A fill designed for a room at 16 °C becomes stifling at 20 °C.
This is why a cool bedroom is sometimes not enough: the air is cold, but the microclimate under your duvet is not.
Why gel is not the answer
The bedding aisle is full of "cooling" gel products. They work — for twenty to thirty minutes.
Gel cools by absorption: it takes in heat until it saturates, then equalises with your temperature and turns lukewarm. The peak of coolness lands as you get into bed, and the effect is gone by the time you enter deep sleep — which is exactly when thermoregulation matters most.
What works over a whole night is not absorption but airflow. An open structure — three-dimensional mesh, ventilation channels — has no capacity to saturate. It vents less aggressively, but it vents all night.
What temperature does not explain
A well-set bedroom does not fix everything, and it would be dishonest to imply otherwise.
Heavy, repeated night sweats that soak the sheets despite a cool room are not a bedding problem. They can accompany hormonal changes, certain medications, or other causes that call for medical advice. If that sounds like you, speak to a doctor rather than a mattress salesman.
Our products act on one variable: how heat moves between your body and your bedding. That is a real, daily variable. It is not the only one, and these are not medical devices.
What you can do tonight
Turn the bedroom down to 18 °C, or open the window a little. Go to bed with warm feet rather than cold ones. And look at what, inside your bed, is stopping heat from getting out — that is almost always where the real obstacle is.
Our answers
Cooling Blanket — built to vent continuously rather than chill in one burst.
Cooling Cervical Pillow — 3D mesh side panels, so your head is not the hot spot of the night.
Read on
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