OTTUMWA — Does breathing outside make you sweat? Is the sun’s angle roasting you with every step you take?

Welcome to the “dog days of summer.” It’s those hot sultry days from early July to early September. The actual dates vary from region to region, depending on latitude and climate.

The traditional timing of the Dog Days is the 40 days beginning July 3 and ending Aug. 11, according to the Old Farmer’s Almanac. That time period coincides with the ancient heliacal (at sunrise) rising of the Dog Star, Sirius.

Jack Horkheimer, my favorite stargazer, has said Sirius “is mentioned in practically every culture that ever kept records.”

Even the ancient Egyptians called Sirius “the Dog Star.” Whenever Sirius was first visible rising before the sun in early morning, that appearance was used as a predictor that the Nile River would soon flood and make Egypt fertile for planting.

Horkheimer said Sirius “is among the very closest of all the stars, only 8.6 light years away.” That means the light we see actually left Sirius 8.6 years ago, which is really close.

Sirius’ closeness has something to do with why it appears so bright but, it’s also almost twice as wide as our Sun and is so much hotter it’s 23 times brighter, Horkheimer said.

In ancient Egypt, astronomer priests began their calendar on the day when “the dog star,” Sirius, rose with the sun, according to Horkheimer.

Then the ancient Romans later discovered that when “the Dog Star” rose with the sun the hottest days of summer occurred and dogs went mad from the heat in Roman streets.

I’ve heard some folks attribute “dog days” to the conspicuous laziness of domesticated dogs, who truly are in danger of overheating with too much exercise during the hottest days. There’s also the connotation of lying or “dogging” around, or being “dog tired”` on these hot and humid days.

These meanings don’t pertain to the original source of “dog days,” but have been attached to the phrase in recent years due to common misunderstanding of its origin.

I think I can link the Dog Star and its “time of the season” to the dogs I’ve known. The weather patterns that occur during the Dog Star’s daytime visits have caused every dog I’ve ever owned to:

• Camp out in the shady spot by his water bowl in the back yard.

• Beg to return to the air-conditioned house.

• Give me the “Are you crazy?” look if I was twirling a Frisbee in my hand.