The idea
I own a Kiva Circadian Sleep Pod. It is a pad that sits on the mattress with water channels in it, and a box beside the bed that heats or cools the water to whatever temperature you set, from about 13 to 40 °C.
It holds one temperature all night. The expensive beds do something smarter: cool for the first hours when deep sleep happens, then ease warmer toward morning so you wake up comfortable. That schedule is most of what you pay the extra A$2,000 for.
The hard and risky parts of a cooled bed are the water loop, the pump and the mains powered heater. I already own those, sealed and certified. All I need to add is something that presses the remote’s buttons on a timetable.
How it will work
- A small microcontroller (an ESP32-C3, about the size of a stamp) sits near the unit.
- It sends the same radio signals as the remote: power, up and down.
- A web page on my phone lets me draw the night’s temperature curve.
- A cheap temperature sensor under the sheet checks the bed actually followed.
The remote can only step the temperature up or down by one degree. It cannot say “go to 24”. So the controller starts each night by pressing down about 30 times, which guarantees the unit is at its minimum, then counts up from there.
What I know so far
- The remote is radio, not infrared. The manual has a pairing step, and infrared remotes never need pairing.
- The unit switches itself off after 10 hours, so the controller needs the power button too.
- The display blinks five times after each change, so presses need a pause between bursts.
What I do not know yet
- Whether the radio is 433 MHz or Bluetooth. That decides which A$10 of parts to order.
- Whether the first press only wakes the display.
- How fast the bed surface follows a change in water temperature.
Evidence, plainly
Moderate at best. Heat clearly harms sleep: one study of about 11,000 nights found sleep efficiency fell 5 to 10% as bedrooms went from 25 to 30 °C. A trial of 72 people on a mattress that draws heat away found more deep sleep and a lower heart rate. But the big claims for actively cooled beds come mostly from the companies selling them. I will measure my own sleep before and after and publish it either way.
Safety line
The controller only ever presses the same buttons I could press myself. I am not opening the unit, not touching mains wiring, and not bypassing its temperature limits. The schedule is capped at 34 °C overnight so a miscounted press can never leave the pad hot.