Dear Readers >> Good morning. Below is a column from 2021 relevant to anyone who has a dog and has a car — or knows someone who does.

And, Concerned Neighbor from last week, I noticed this weekend that water from the Oligarchy Ditch is pouring into McIntosh Lake. — Johnnie

Dear Johnnie >> A couple of weeks ago (early June), I had lunch with a casual friend. The weather was warm and sunny so we ate outside, near where her car was parked, in full sunlight.

Towards the end of the meal, I noticed that she had left a dog in her car. I immediately expressed concern, but she insisted that since the temperature was only in the mid-80s and her windows were cracked open, the dog would be just fine. I was appalled, and ended our lunch a short time later.

In retrospect, I wish I had suggested that she try sitting in that car for an hour and see how just “fine” it was. Cars get really hot in the sun, and I doubt she would have lasted 10 minutes.

She reads your column, so maybe you can quote a few facts and figures for her and all other dog owners out there. Hot weather is no time to leave a dog (or child) in the car!

Thank you. — Leave Your Dog at Home

Dear Leave Your Dog >> I conducted a little test in the Johnniemobile.

About lunchtime on a day similar to the one you describe — partly cloudy to sunny and in the low to mid-80s — I checked a thermometer I keep in the vehicle, which displays the temperature inside the cabin and out. The cabin temp was 84 degrees, which was just a degree or two higher than the outside temp at the time.

Then, I cracked all four windows, each a little more than a thumb’s width, and placed my sunshade inside the windshield. Then I went into the office and set a timer for 30 minutes.

When I went back out to check the cabin temp, I found that it had risen to 97 degrees. Another half hour later I went back out. It was 101 degrees inside the vehicle, but only 84 degrees outside. And that was facing generally away from the sun, with the sunshade and tinted rear windows.

That’s far too hot for a dog to be sitting in a vehicle.

“It can happen quicker than people think,” veterinarian Nancy Bureau said of heat stroke, which is a real danger for dogs left in cars, even at cooler temperatures.

Why are cars a particular problem? We’ll start with how dogs cool themselves.

Since they have sweat glands only on their paw pads, dogs primarily use panting to cool off. According to the American Kennel Club, panting allows dogs to exchange their body heat via their tongues, nasal passages and the lining of their lungs. Additionally, blood vessels in their ears and face expand, allowing overheated blood closer to the surface.

So, when a dog is stuck in a vehicle in which the only available exchange air is hot, the dog cannot cool down and its body temperature can rise rapidly. A dog’s normal temperature, according to the AKC, is about 101.5 degrees. If its temperature rises to about 105 degrees, the dog can suffer from heat stroke.

“We usually see a couple of heat stroke animals per year, usually early in the season when people think its still cool enough,” said Bureau, who works at Left Hand Animal Hospital. “It takes just a few minutes.”

How quickly a dog can succumb to the heat can depend on air flow, the breed of the dog (short-nosed breeds don’t cool off as easily), the availability of water, and whether the car is parked in the shade, she said.

But it’s better to not leave the dog in the car to start with.

“When a dog overheats, it’s because the pet parent didn’t realize the threat,” Bureau said.

And, she said, heat can harm a dog even outdoors if it doesn’t have access to shade or water.

The early signs of heat stroke are “heavy panting, trying to seek coolness, trying to get to shelter,” Bureau said. “Then past that, they’ll look wobbly, dizzy, they might throw up. Then bad, bad things can happen.”

If your dog is showing such symptoms, cool him down as quickly as possible, offering water and even using ice. Then get him to a vet as rapidly as possible.

Cats, too, can overheat as dogs do. However, as Bureau said, “Cats tend to be more clear about ‘I’m not doing that in the heat.’ “

— Send questions to johnnie@times-call.com.