Debunking Myths of Leaving Your Dog Unattended in Your Car


Sadly there are still many erroneous misconceptions out there surrounding the idea of leaving pets in parked cars. These contribute to dangerous practices that result in the heat stroke cases and deaths that Lange Animal Clinic associates are seeing on a daily basis and that we all read about in the news and online way too often.

We want to debunk these misconceptions and do our part to put a stop to these dangerous practices. Use it to educate yourself and protect your pets, and share it to help educate others. The more people we can get to recognize the inherent dangers of these misconceptions and practices, the more injuries and deaths from heat stroke in pets we can all help to prevent.

Misconception #1: “I leave the windows cracked in the car to let air in”

The Reality: Multiple studies have shown that leaving the windows cracked has only a minimal, and overall insignificant protective benefit.

Studies have shown that the average temperature rise of 3.4°F per 5 minutes in an enclosed car was only decreased to 3.1°F per 5 minutes by ‘cracking’ the windows. This equated to a difference of only 3.6°F over the 60-minute study period (40.8°F total heat rise with windows fully closed, compared to 37.2°F rise with windows ‘cracked’).

Another study showed only a 2°F difference at the end of the 90-minute study period between a fully enclosed vehicle and one with the windows ‘cracked’.

As you can see, while cracking the windows does have some effect on slowing down the temperature rise inside a car, the effect is very minimal and it’s not enough to prevent the temperature inside a car from quickly rising to deadly levels.

Bottom Line:

  • Do not leave your pets or kids alone in parked cars.
  • Cracking windows, short periods of time, relatively mild days, leaving water, or running the air conditioner do not make a parked car a safe place for a pet to be alone.
  • Educate yourself and your loved ones to protect more pets.

Misconception #2: “I’ll only be gone for a few minutes”

The Reality: Whenever you run into a store there are plenty of factors that are outside of your control and which can prolong your time away from your dog.

Consider a longer than usual check-out line, bumping into a friend or neighbor, forgetting something from your shopping list, or even a slip and fall. There really are many unforeseen things that could realistically and significantly delay your return to your car. And that delay can result in your dog suffering (and potentially dying) from heat stroke.

The next time you dart into a store for a “quick shopping trip”, time yourself. Do this exercise a few times and see how long “a few minutes” can actually be. Then keep the following numbers in mind:

19° – that’s the average °F temperature increase in a parked after just 10 minutes in one study
29° – the average °F temperature increase after just 20 minutes
34° – the average °F temperature increase after 30 minutes
43° – the average °F temperature increase after 60 minutes

Now imagine what this would equate to on a relatively mild 80°F day. Imagine what it would be on one of the 100°F days that are common in certain areas, and are becoming more commonplace in others. The results can be devastating.

Misconception #3: “It’s only 70°F out, there’s no danger of heat stroke

The Reality: Temperatures in the low 70’s are plenty hot enough to cause a dog left in a parked car to develop and suffer from heat stroke.

In fact, the study cited above was conducted in San Francisco on a series of relatively mild days. On one of the 72°F days during the study the temperature inside the test car reached 93°F in 10 minutes, 105°F in 20 minutes, 110°F in 30 minutes, and 119°F in 60 minutes! Plenty hot enough to cause heat stroke.

Not only is 70°F warm enough to result in heat stroke, even temperatures in the low 60s can be dangerous for some pets. This is because certain cats and dogs – based on factors such as breed, weight, existing medical conditions, and several other factors – are actually more sensitive to heat than others, and therefore at even greater risk of developing and suffering from heat stroke.

Misconception #4: “I always leave water in the car for my dog, so I don’t have to worry about heat stroke”

The Reality: Though leaving water is a good thing, as it can help to prevent dehydration and heat exhaustion, it does very little to stave off heat stroke in parked cars.

The reason is that dogs rely mostly on the evaporative cooling effects of panting to get rid of excess heat, and their ability to do so effectively is quickly overwhelmed in a hot, stuffy car- regardless of whether or not they have a water bowl in front of them.

Misconception #5: “I leave the air conditioner running, so I don’t have to worry about heat stroke”

The Reality: Air conditioner compressors and car engines fail, and dogs knock into and inadvertently press and hit buttons and switches.

Sadly there are plenty of cases of dogs dying when the car air conditioner failed or a dog bumped into and switched off the air conditioner.When air conditioner compressors fail, the air blowing into the car from the vents often turns from cool to hot, greatly speeding up the temperature rise within the car.

Generally speaking, it is never a good idea to leave your beloved dog in a car alone for any extended periods of time.  Please take precautions when travelling with your pets to ensure their good health and safety to avoid the possibility of heat stroke and death.

For over 45 years, Lange Animal Clinic has provided veterinary services in Pekin, IL and the surrounding areas for over three family generations. Our expert staff of Veterinarians, Veterinary Technicians, and Veterinary Assistants are trained to ensure the best quality medical care for your beloved pets-whether it be as a routine medical examination to more complicated surgical procedures. We are a small companion animal clinic providing services for dogs, cats, and exotic pets.

Dr. Colleen O’Rourke, owner and senior Doctor of Veterinary Medicine, takes great pride in making certain that every patient’s experience is handled with the utmost care, compassion, and economically in the best interests of our clients. Visit us at  

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