We are inclined to measure our seasons with thermometers because numbers are exact. They inform us with precision at this time of year about how many layers we will need to stay comfortable: add flannel in the 50s, sweaters in the 40s, jackets in the 30s, hats and scarves in the 20s, and take a day off at home by the fire in the teens.

But our sense of Jack Frost’s cold touch is only the most obvious of our senses at this time of year. The sights, sounds, and smells of fall — and even the tastes of autumn’s orchards — are seductive enough to make us forget that shiver down the spine when we step out in the morning air after a hard frost.

That killing frost came to our house last Friday, laying low the garden’s late bloomers and blanketing the world with its fuzzy freeze. Kate, just in with the morning paper, dragged me back out with her into the predawn darkness. “Listen,” she said.

Moving wood for the winter from the outside stack to the shelter of the back porch is always a pleasant chore. It’s October, and the world burns with color. The air is cool, and Kate and I shed flannel as we warm to the work. Despite the splinters, pinched fingers and, later on, sore muscles, we are always deeply satisfied when the work is done.

We have an oil furnace and, in the colder corners of the house, electric baseboard heat, and we could just skip all the heavy lifting by paying a premium to run these utilities overtime in the coming months. But for us, burning wood in the fireplaces and woodstove is not just a matter of BTUs. The various rituals associated with keeping the home fires burning provide footholds that help us find our way through the darkness of winter. Stacking wood in a dry place, splitting kindling, cleaning ashes beneath the grates, fiddling with dampers and pokers, and keeping the fire not too hot and not too cool is a far more hopeful enterprise than sitting by a fitful radiator peering out the window into the dark. Even in a blizzard, we know the smell of wood smoke can lead us home.