“Swim: Why We Love the Water” by Lynn Sherr; c.2012, PublicAffairs; $25.99 / $29.00 Canada; 213 pages, includes index
You’re a little scared.

Looking at the temperature these days is not for the faint of heart. The red line on the thermometer has to be somewhere in the Hades which means the less you know, the more comfortable you’ll feel – although you won’t be totally comfortable until you get home and slip into the dip, take a cool plunge, have a cold drink while lounging in the drink.

You need to go swimming.

But why do we – land animals that we are – spend so much time trying to be fish? In the new book “Swim: Why We Love the Water” by Lynn Sherr, you’ll wade into the answer.

It doesn’t take much to imagine the first human who joyfully leaped into the water.

Ancient Egyptians were so familiar with swimming that they created hieroglyphs for it. A cave in the Eastern Sahara not only proves that there was water there once, but that humans swam in it. Early Greeks created coins depicting a skinnydip, and Roman noblemen thought swimming was one of “the manly arts.”

Yes, humans swam until about the late Middle Ages… and then we stopped, for reasons that historians can only guess at. For about 500 years, we shunned water – possibly because of its lack of cleanliness – but by the latter 1500s, humans were once again splashing away and inventing ways to get wet.

While Native Americans and Africans had “practiced the art with natural grace,” Sherr says that white Americans “struggled with the proper way to enjoy the water.”

It didn’t take long for them to figure it out, though, and it didn’t take long for them to deny their darker brethren a chance to dip their toes in the pool. Even today, 60 percent of African American children don’t know how to swim.

For water-lovers, a lot has changed over the centuries, including the water itself: pools are much cleaner than 11th-century moat swimmers found. Swimsuits are racier, and racing results are more precise. Various strokes have been “invented” and most are scientifically measured for speed and efficiency. Even the way we enter the water is different than it was a hundred years ago: chances are that your bashful great-grandma got wet by wagon.

Beginning with a legendary challenge that took her on a swim from one continent to another, author Lynn Sherr strokes readers’ curiosity and gives us plenty of excuses to go jump in the lake. She glides from psychology to seaside, from bathing beauties to beach bums, and from ancient Greece to swimmer’s grease here.

What sets this book apart, though, is that Sherr’s words are as meditative as the act about which she writes. You’re lulled into the kind of relaxation you’d get from a 75-degree pool, but Sherr will also surprise you with splashes of sidebars that are pure fun.

If you’re sometimes regretful that you don’t have gills, or if you spend most of your workday thinking about your pool, then “Swim” is definitely your kind of book. Grab a copy, and dive right in.

The Bookworm is Terri Schlichenmeyer. Terri has been reading since she was 3 years old and she never goes anywhere without a book. She lives on a hill in Wisconsin with two dogs and 12,000 books.