sleep temperature, measured
one duvet.
two thermostats.
One of you sleeps hot. The other sleeps cold. You share one cover, and at 3am somebody loses.
pillowz reads your room, your bodies and the bedding you already own, then writes the bed you should build instead.
The Intake is not open yet. There is no email list here and nothing to join.
The spike is not the mattress. It is a 74°F room under a sealed cover, and it arrives on schedule.
The blanket is usually not the problem.
A $249 cooling blanket changes how the top layer feels. It does not change a room at 74°F, a cover that seals, or two people who need different tog.
74°F
ambient at bedtime
The room is the strongest lever in the research, and almost nobody measures it.
1 tog
shared by 2 bodies
One cover cannot be right for both of you. The hot side needs 3 tog less.
0.4 tog
polyester cover
A good down duvet inside a sealed cover behaves like a cheap one.
the bed, layer by layer
| duvet cover | polyester sateen | traps |
|---|---|---|
| duvet inner | down, 10.5 tog | one tog, two bodies |
| flat sheet | cotton sateen, 300 TC | low airflow |
| fitted sheet | cotton percale, 180 GSM | wicks |
| protector | polyurethane film | vapour barrier |
| mattress | foam, 11 in | stores heat |
One example bed, from one Intake. Yours will differ, which is the whole point.
What $524 usually buys.
Three purchases, most of it returned or in a closet. The two changes with the strongest evidence cost nothing at all.
We rank every $0 change above every change that costs money. A $40 percale set can beat a $249 hero product, and we will say so.
| what people try | cost | changes | evidence |
|---|---|---|---|
| cooling weighted blanket | $249 | surface feel | Thin |
| phase-change sheet set | $180 | surface feel | Thin |
| bamboo viscose duvet cover | $95 | airflow | Moderate |
| pre-cool the room to 68°F | $0 | ambient | Strong |
| turn the fan to exhaust out the window | $0 | ambient | Strong |
Swipe the table to read the Evidence grade.
You pay $29 and the first thing we say is: spend nothing.
A Bed Spec opens with Findings — why this bed runs hot, in numbers. Then the Changes, ranked. Change 1 costs $0.
Findings
This bed runs hot mostly because of the cover, not the duvet. Ambient at bedtime is 74°F, six degrees above where the hot side settles. The hot side needs 4.5 tog; the cool side needs 7.5 tog.
Changes, ranked
- Change 1Take the polyester cover off tonight. Sleep under the duvet inner.$05 minModerate
- Change 2Pre-cool the bedroom to 68°F from 21:30, and close the door.$010 minStrong
- Change 3Turn the fan to face out of the window, not at the bed.$05 minModerate
- Change 4Split the layers. 4.5 tog on the hot side, 7.5 tog on the cool side.$64one orderModerate
spend nothing until Change 4
Picks name material, GSM or tog, price and retailer. We take no commission on anything here.
We grade our own evidence down.
A 2025 systematic review of cooling bedding (Pasquier & Chauvineau et al.) found body-cooling effects but no convincing improvement in sleep parameters, at low to very low certainty.
The evidence on ambient temperature is stronger. So a Spec spends your money on the room before it spends it on fabric.
- Strong
- Repeated controlled data. We act on it and we say why.
- Moderate
- Real data, small or mixed. Worth doing, worth measuring.
- Thin
- Marketing, anecdote, or one study at low certainty. We say so.
No brand pays to appear in the Catalog. There are no affiliate links, and there never will be.
Change 3, drawn. The fan faces the window, not the bed. Cost $0, Evidence grade Moderate.
Then fourteen nights of tuning.
A Spec is a hypothesis until it is measured. Fourteen nights turn it into your data, not our claim.
- 01
Night check
Two taps at bedtime. How hot the hot side ran, and how many wake-ups.
- 02
One adjustment
One email at 07:00 with one thing to change. Never a list of ten.
- 03
The trend
Your own line, redrawn every night. Changes that stop working get dropped.
After Night 14 the emails stop. If the trend did not move, the verdict says so and puts the refund first.
one price, one deliverable
$29 spent knowing
beats $249 spent
guessing.
One Bed Spec, two sleepers, fourteen nights of Tuning. No account, no password, no subscription.
- Bed Spec
- $29 once
- Heat Score
- free
- refund on request
- 30 nights
- commission we take
- $0
The Heat Score is free and asks for no email. You only pay if you want the Changes that go with it.