Rest
The Temperature of Rest
Thermostats were invented for houses, not for bodies. A short piece on the degree or two that quietly rearrange a night, and the household inheritance that keeps us from noticing.
Our thermostats, mostly, were set a long time ago by someone who was not thinking about sleep. If you own your home, that person was probably you, three or four years ago. If you rent, that person was probably the landlord, who turned up the heat the first winter and never thought about it again. In either case, the room you sleep in is almost certainly a few degrees too warm.
What the body is trying to do at night
Falling asleep is a cooling process. The body sheds a small amount of core heat during the first part of sleep, routing warmth out to the extremities. If the room is cool enough, this handoff happens easily and the body quiets. If the room is warm, the body has to work a little harder to lose that heat, and the quieting is slower.
You feel this most clearly in a hotel. A good hotel room, the kind where you sleep deeply even though the bed is strange, is usually colder than you keep your own house. If you have ever had the experience of sleeping better on a trip than at home, it was probably not the sheets. It was the temperature.
The number, roughly
The number, roughly, is 65°F. Give or take a couple of degrees. Some people run a little warmer, some a little cooler. The range inside which a bedroom becomes a good room to sleep in is narrower than most people expect, and almost all of us have the dial pointed somewhere above it.
If you want to run the experiment, the bar is low. Drop the thermostat two degrees for a week. Add a slightly heavier blanket if you need one. Pay attention, not to how it feels at first, but to how it feels at four in the morning, which is the hour that will tell you whether you got it right.
A small inheritance
There is a quiet inheritance in how we heat our houses. We learned it from our parents, who learned it from theirs. Most of us keep bedrooms at the temperature we grew up in, and most of us never notice that this is a choice. It is one of the easiest and cheapest things to change about a night, and almost nobody does.
Turn it down. See what happens. If nothing happens, turn it back up. You will not have broken anything. The thermostat does not have feelings.