I always figured the Fahrenheit temperature scale was arbitrary, inasmuch as zero degrees Fahrenheit and 100 degrees do not seem to correspond to anything, such as water boiling or freezing.

But after living and visiting in the Southern latitudes and then living in Maine, I now have a theory.

The temperatures of 100 degrees and zero degrees represent the ends of the livable temperatures, beyond which life becomes unbearably uncomfortable and even threatened unless you take adaptive measures. What you were doing and wearing before just won’t work past these extremes.

One day long ago, in August, I was visiting Pocahontas, Ark., my early roots. For some reason, I struck out walking to downtown at l p.m. Yes, it was miserably hot, but it was always miserably hot there in August.

When I looked around and realized that no other person was walking, I remembered. The day was to be over 100 degrees. It could be dangerous to be out walking in that midday heat. The locals all knew better. I went back to the hotel and jumped into the pool.

Then, some years later, in early January I was cross-country skiing with my new equipment in the Arboretum in Augusta. I knew it was cold, but it was always cold in early January in those days. Then I looked around and saw no one else was skiing.

Then I remembered. The day was to be below zero. It could be dangerous to be out skiing in that cold! Especially alone. The locals all knew better. I went home and had hot European coffee.

I have since skied, both cross-country and downhill, in temperatures below zero, but I know to put on three layers instead of the usual two, to use two caps instead of one, to cover my face somehow and to wear special gloves under the insulated ones. I know my usual procedures no longer will work; I must take adaptive measures.

My best adaptive measure for temps above 100 is to stay the heck out of it, or to be in a cold body of water. I’ll go on record as saying I hate hot, humid weather and have spent too much of my life in it. That’s one reason I’m in Maine. If I had to choose between over 100 or under zero, I’d choose the latter. I can dress for it, and rather enjoy the challenge of weather that cold, from time to time.

But I do have great respect for such cold. It sneaks up on you and causes your body to slowly stop functioning.

A late-night scare

I had a bit of a scare the winter before last. We had “an old-fashioned winter,” with lots of the real deep-freeze. When I got out of my part-time job at 11 p.m., it was already minus 10 degrees; I hopped in my older car, warmed it up my usual half a minute and drove the 12 miles home. My car never warmed up at all. I was wearing what I discovered were wimpy gloves, and my hands were growing more and more numb every minute of the drive home.

By the time I got home my almost-useless hands could hardly get the house keys out of my purse. Once the keys were out, my hands weren’t holding them well enough to insert them into the doorknob, then the deadbolt and then turn them.

I almost panicked when I realized my husband was upstairs sleeping and would never hear me knocking if I couldn’t get in. I would run into the same problem if I tried to get into my car and start it again to go somewhere else.

But I pulled myself together and concentrated on getting those keys into their slots and turning them. I got in!

Now I have a working door chime, I keep heavy-duty gloves in my car year-round, and I warm my car up much longer before I drive off when it’s below zero.

I respect the cold. Now I think our Fahrenheit scale is a good indicator of what is a survivable temperature, and what lies beyond.

Dianne Russell Kidder is a writer, consultant and social worker, who is based in Lisbon. She is a regular contributor to this column. She can be reached by e-mail at [email protected].