Our bedroom thermometer got me thinking seriously about the metric system.

The thermometer is what’s left of an indoor-outdoor thermometer we used to have. It’s been such a long time since it stopped working, I’m not even sure what happened anymore. There may have been a wire connecting it to an outside sensor, and by flipping a switch, you could find out what the temperature was outside and inside. It is digital, and it was pretty cool. But it broke. The wire broke? I don’t know.

So we’ve kept it in our bedroom to keep track of the temperature. Our bedroom is the hottest room in the house in the summer and the coldest in the winter, and it’s always good to know what the temperature is when we go to bed or wake up. If it says 64 degrees and it’s fall or winter, that’s too cold, and we say so. If it’s 77 degrees in the summer, that’s too hot to sleep, and we say so. And we let it go at that.

I pack it when we go camping so we know how to dress in the morning – not that shivering doesn’t mean it’s too cold, and it’s best to dress in layers. The lowest it registered was 39 degrees the first morning after Memorial Day in Yellowstone, and it recorded 48 degrees just after Labor Day on Lake Superior. That’s chilly. And it was good to know what we were up against.

I trust the accuracy of the thermometer. It keeps roughly the same temperature as the digital weather station-atomic clock in the living room. That was supposed to be an indoor-outdoor thermometer, too, connected by radio waves, but the outside sensor stopped working, so it only gives the indoor temperature, humidity and an animated barometric pressure, as well as the accurate time and date.

But the bedroom thermometer started acting up on our last camping trip. Instead of giving the temperature in Fahrenheit, it would switch to Celsius, which is metric, and I had no idea what the temperature was, except that it felt chilly. But chilly could be 48 degrees or a balmy 55 degrees in the tent, and that makes a big difference in how you dress.

And I couldn’t do the math. It’s not easy to convert from Celsius to Fahrenheit. You take the degrees in Celsius, multiply by 1.8 and add 32, hardly the calculation I’m going to remember or do without a calculator first thing in the morning, or any time, for that matter. To convert Fahrenheit into Celsius, you take the Fahrenheit temperature, subtract 32 and multiply by 0.5556. Simple. I had to look that up.

So, when the thermometer was displaying 8.9 degrees Celsius, it was actually 48 degrees Fahrenheit. Definitely chilly. But I wouldn’t have known without a calculator. And I’m not that desperate. If I pushed the light button – yes, it has a light – long enough, it would switch back to Fahrenheit. Go figure.

According to the Incredible Internet, there are some benchmarks to help you understand what Celsius feels like. Zero is the point at which water freezes, 20 degrees is room temperature, 37 degrees is body temperature, and 100 degrees is the boiling point for water. So 30 degrees is uncomfortably hot at 86 degrees Fahrenheit, but 25 degrees isn’t too bad.

The United States, Liberia and Myanmar are the three countries in the world that have not converted to the metric system, according to various reports on the Incredible Internet, although some countries use a mix of the metric system and the English imperial unit, mostly because old people refuse to switch over. Among the top 10 reasons why the United States should switch to the metric system is this little gem: “So we look less foolish and ignorant to the rest of the world.” Ouch.

I’m reading a book, “The Martian,” which was made into a major motion picture this fall, and all the units of measure are metric – meters, liters and grams. And I can only guess at what Mark Watney is measuring. I do feel “foolish and ignorant” reading the book, not knowing how fast 25 kilometers per hour is, and the examples could go on and on. I should know this stuff.

In my heart of hearts, I’ve always felt the U.S. should take a deep breath and switch to the metric system, which is based on simple math and units of 10. We’ve all gotten used to 2-liter bottles of pop, which is the one true metric unit that has taken hold in the U.S. Police measure confiscated narcotics in grams, which is a step in the right direction, although I still don’t have a clue as to how much they are really talking in ounces and pounds. And there are 5-kilometer and 10-kilometer runs.

Let’s catch up with the rest of the world and switch to metrics. Our broken bedroom thermometer is already there.

• Dick Peterson, who live in Woodstock, is a mental-health advocate. He is a freelance writer and a former Northwest Herald Opinion Page editor. He can be contacted at dickpeterson76@gmail.com.