It was a sunny day with temperatures in the mid-80s. A beautiful yellow Labrador retriever sat in the front passenger seat of a black car parked in a school parking lot.

What's a dog lover to do? Here's what I did:

I stopped, parked my car and went to see how the dog was doing. He was panting slightly, but did not seem to be stressed or dangerously overheated. I watched him for 10 minutes. Then I called 911.

I told the nice dispatcher that the dog didn't seem to be in trouble yet. The car was shaded by a tree and the windows were cracked about 3 inches. I gave the dispatcher the address, the make and model of the car, and the license plate number. I said I would stay to watch the dog. The dispatcher said he would call the local police department.

I don't normally like butt-in-skis, but every year dogs and children die when left alone in hot cars. Temperatures inside a car can top 100 degrees in less than an hour, according to many studies.

Do a Google search for "dogs left in hot cars" and you'll find lots of sad stories about dead canines, including a June 2009 Pet Tales column about Buddy, a Westmoreland County Rottweiler. Buddy's trainer put several dogs in a van and took them to a groomer. Somehow, someone forgot to unload Buddy and he spent four hours in the hot vehicle. He died, and his owners shared his story, hoping to prevent other owners from experiencing their heartbreak.

Every summer I do a column about dogs in hot cars. No one seems to keep track of how many dogs die this way. This year, however, I found a Washington Post story about the 15-25 infants and toddlers who suffer "death by hyperthermia" every year in the United States.

What kind of parents forget to take their children out of a hot car? In the past 10 years, their ranks included a postal clerk, social worker, police officer, soldier, minister, rabbinical student, nurse, college professor, pediatrician and a rocket scientist.

This information comes from a story headlined "Fatal Distraction: Forgetting a Child in the Backseat of a Car Is a Horrifying Mistake. Is It a Crime?" The writer, Gene Weingarten, deservedly won the 2010 Pulitzer Prize for feature writing. The story, which undoubtedly will help prevent some deaths, can be found on the Internet.

Last Saturday, I watched the Lab for 25 minutes before the owner showed up. He gave the dog an affectionate greeting. I wish he would have given the dog some water.

Because the nice dog survived, I guess I should have just driven away. But the guy seemed clueless, and I feared the dog might not survive the next outing. So I politely told him about the Washington Post story, and I said I had called 911.

He screamed at me, "The car is in the shade and the windows are cracked!" He got into his car, slammed the door and screamed even louder, "GET A LIFE!" He made an obscene hand gesture as he drove, too fast, out of the parking lot, past parents and children whose baseball game had just ended.

I believe he honestly thought his dog was in no danger. Researchers at Stanford University would disagree. On days when the outside temperature is a pleasant 71 degrees, the temperature inside a car rockets to more than 116 degrees after an hour in the sun, according to a study whose lead author was Catherine McLaren, a medical doctor in the department of emergency medicine at Stanford University. Keeping windows open a crack hardly slowed the temperature rise at all, the study found.

This week I conducted my own unscientific experiment. With a nice breeze blowing through windows lowered about 3 inches, the temperature inside my own car rose from 74 degrees to 121 degrees in 35 minutes. The temperature outside was 71 degrees -- much lower than mid-80s that the Lab was subjected to.

I called 911 to cancel my report. I'm not faulting the local police for not showing up. They were probably responding to more pressing calls. I would have called again if I thought the dog was in danger of dying.

Just out of curiosity, I asked my local police department what a dog lover should do when we see one in a hot car. Lt. Aaron Lauth of the Mt. Lebanon Police Department said, "Definitely call 911 if you believe an animal is in distress. We get two or three calls each summer" about dogs left in cars, and police do respond.