There is a moment, most nights, when the body asks to be a little colder than the room. It is not discomfort — it is design. Core temperature falls by roughly a degree as we move toward deep sleep, and that descent is part of what triggers the night's most restorative work. Warm the room too much, or trap the heat against the skin, and the descent stalls.
The case for cool
Sleep researchers have circled the same finding for decades: a bedroom held somewhere between 16 and 19°C tends to produce deeper, less fragmented sleep than a warmer one. The number matters less than the principle. The body wants to shed heat at night, and it wants a surface that lets it.
We do not sleep well in spite of the cold. We sleep well because of it.
Why linen, not cotton
This is where material stops being decoration. Stonewashed heavy linen is hollow at the fibre and loosely woven at the cloth, so it breathes in both directions — wicking warmth away on a close night, holding a little back on a cold one. Cotton, by contrast, tends to hold moisture against the skin. A good linen sheet is not softer than cotton on the first night. It is better on the thousandth.
A small ritual
Lower the room a degree before bed. Choose bedding that moves air rather than trapping it. Let the descent happen. The science is unglamorous and the effect is profound: you wake having actually rested, rather than merely having lain down.
It is, in the end, the whole EVAR argument in miniature — that the considered object, chosen for how it performs over years, quietly changes how a life feels.