MINNEAPOLIS (WCCO) — This week, scientists in Sweden celebrated one of their own. Anders Celsius would have turned 318 years old on Monday.

So, we thought we’d take this chance to answer a Good Question you’ve been asking for years: Why does the U.S. measure temperature in Fahrenheit?

“People are familiar with the system,” says Don Hillger, president of the U.S. Metric Association. “When you ask them to change to a different one, it’s a challenge and there’s a lot of inertia.”

The U.S., Belize, the Bahamas and Cayman Islands are the only countries who still officially use the Fahrenheit system.

The Fahrenheit scale is named after Daniel Fahrenheit, an Amsterdam physicist who invented it in 1724. Historians believe he set zero as the coldest temperature he could create in a lab and 96 as the human body temperature. The freezing temperature – 32 – fell in between.

Later in the 18th century, Anders Celsius came up with a new measurement system for temperature. His scale set zero for freezing and 100 for boiling. The French later included that measurement as part of the metric system.

It would take hundreds of years, but almost every country eventually followed along.

“I mean, 5,280 feet to the mile, where did that number come from?” says Hillger. “Why not tens and hundreds and thousands, it makes so much more sense?”

The U.S. is considered a non-metric country, but some American industries do use metric measurements. Food nutrition labels are measured in grams. Many carmakers and medical device companies use metric measurements.

In 1975, Congress passed the Metric Conversion Law. It was voluntary and not well-received. It was dissolved in 1982. Hillger says for anything to change now, Congress would have to approve it and a public relations campaign would be necessary. He says classrooms would also have to focus on Celsius more in schools.

“Scientists, of course, are already on the bandwagon,” he says. “They like things as simple as possible.”

To convert temperatures in degrees Fahrenheit to Celsius, subtract 32 and multiply by .5556 (or 5/9).