The Facts

By Jon Sutz, Founder, HEATKILLS.us™


Contents

(1) Summary

(2) Quotes by experts about the why it is so dangerous to leave a dog in a car - even on a seemingly "cool" day

(3) Doesn’t leaving the windows cracked an inch or two make a difference? No.

(4) Videos showing how quickly the interior temperature of a car rises in sunlight

(5) Tips for helping a dog that you suspect is suffering heatstroke


(1) Summary

Here are the three most vital facts about canine physiology and heatstroke that every dog owner, and every person who cares about their well-being, should know. The sources for this data are in Section (2).

  • Dogs can't sweat, and they are covered in fur.  This is why dogs have died from heatstroke in cars even when the outside temperature was only 70 degrees.
  • Dogs can begin to suffer brain and organ damage in as little as ten minutes, when left in a car.
  • Even with its windows partially open, a car's interior temperature can rise 19 degrees in ten minutes, and 29 degrees in twenty minutes.

To get an idea of the general public's tragic unawareness of these basic facts, see the nearly 150 comments on this video.

This lack of awareness, and misconceptions regarding heatstroke and dogs, is exactly what leads to near-daily news stories during the spring-summer-fall months, of dogs suffering unimaginable agony after being left in hot cars.

Section 2, below, contains scientific information about how and why dogs suffer in hot cars.

Here is a compilation of some of the stories of individual dogs who endured this agony, many of whom did not survive:

Tragic stories of dogs suffering, and dying, in hot cars – HeatKills


(2) Quotes by experts about the why it is so dangerous to leave a dog in a car - even on a seemingly "cool" day

"Never leave your pet in a parked car when the outside temperature is above 70 degrees. Not even with the windows partway down, not even in the shade, not even for a quick errand. Dogs and cats can’t sweat like humans, so they pant to lower their body temperature. If they’re inside a car, recycling very hot air, panting gives no relief, and heat stroke can happen quickly."

Best Friends Animal Society (BFAS is one of America's most respected animal welfare and rescue nonprofits)

"Even on a seemingly cool day, even with the windows partially opened, it can be dangerous or deadly to leave a dog in your car."

- Ernie Ward, DVM, author of “Chow Hounds: Why Our Dogs Are Getting Fatter -A Vet’s Plan to Save Their Lives.”

When temperatures outside range from 80 degrees to 100 degrees, the temperature inside a car parked in direct sunlight can quickly climb to between 130 to 172.

– Centers for Disease Control and Prevention data, cited in Hospital CEO Leaves Child to Die in Hot Car - ABCNews.com, July 5, 2001

“Heat stroke can occur when an animal’s temperature rises to a critical level. Normal body temperatures for dogs and cats range from 100 to 102.5 degrees. When a dog’s temperature rises to 108 degrees, or a cat’s to 106 degrees, they can suffer irreparable organ damage and even die.”

Michael Dix DVM, Medical Director, Best Friends Animal Society

"Even on a relatively cool day, the temperature inside a parked car can quickly spike to life-threatening levels if the sun is out, researchers at the Stanford University School of Medicine have found. They hope their findings will put to rest the misconception that a parked car can be a safe place for a child or pet in mild weather. 'There are cases of children dying on days as cool as 70 degrees Fahrenheit,' said lead author Catherine McLaren, MD, clinical instructor in emergency medicine. Though past research has documented the temperature spike inside a car on extremely hot days, this is the first time anyone has looked at cooler days, she added."

Stanford University research

"Permanent brain and organ damage can occur (in dogs) when the body temperature reaches or exceeds 106 degrees. If heatstroke is severe and left untreated, coma and death can occur."

– Carol Osborne, DVM, cited in Warning Signs of Heat Stroke in Dogs, Reader's Digest, March 17, 2022

“Children have died in cars with the temperature as low as 63 degrees. Basically the car becomes a greenhouse. At 70 degrees on a sunny day, after a half hour, the temperature inside a car is 104 degrees. After an hour, it can reach 113 degrees.”

Jan Null, adjunct professor at San Jose State University

In response to an interview question about his observations regarding accurate knowledge among authorities - police, lawmakers, SPCAs - Ernie Ward, DVM, one of America’s most famous and influential veterinarians, said:

It’s very elementary. I was contacted recently by someone in a situation in which it was apparent that law enforcement wasn’t really aware of issues concerning heatstroke danger.

"Many also don’t know that older dogs are the most vulnerable, and can actually suffer hidden damage, such as in the case of renal failure. A lot of these dogs, the symptoms don’t actually show up until a month later, but they were accelerated by an event in a hot car."


(3) Doesn’t leaving the windows cracked an inch or two make a difference? No.

"Leaving the windows [of a car] opened slightly does not significantly slow the heating process or decrease the maximum temperature attained."

American Academy of Pediatrics study


(4) Videos showing how quickly the interior temperature of a car rises in sunlight

An informational video by General Motors


A video by a frustrated veterinarian

Ernie Ward, DVM is a noted veterinarian based in North Carolina, and author of the book, “Chow Hounds: Why Our Dogs Are Getting Fatter -A Vet’s Plan to Save Their Lives.”

Learn more about Dr. Ward at his website.

He made this video on an impromptu basis, after his frustration boiled over at seeing another dog -- this one owned by a customer of his clinic -- being put at risk of heat stroke. It has now more than 2 million views:

Also, here are some comments Dr. Ward made during an interview I did with him (for my predecessor site, HeatKills.org):

I had seen cases over the years of dogs having been confined in hot cars. But it was one particular incident, on a Saturday, that inspired me to do the video. I was working at the clinic, when a woman came in to pick up medicine for her dog.

We were busy, and the clock was ticking. I knew she had her dog with her, and ten minutes had passed. I expressed concern about her dog, but her response was basically, “Oh it’s okay, I left the windows partially open, and it’s only been a few minutes.”

I replied, “No, it’s been over ten minutes.” She was unaware of the danger, so I explained it to her – that even on a seemingly cool day, even with the windows partially opened, it can be dangerous or deadly to leave a dog in your car.

So a little while later, after the clinic closed down, I just decided to go film myself in a car, to show what happens to a human being when confined in such an environment."


(5) Tips for helping a dog that you suspect is suffering heatstroke

As my predecessor site (HeatKills.org) became more well-known, I spoke to numerous veterinarians and veterinary college professors about the proper means of providing first aid to a conscious dog that may be suffering heatstroke.  The impetus for my research was a report I produced about a local SPCA that created and distributed an informational flyer that contained instructions for treating a dog in heatstroke that in reality would make the dog worse, or even kill it.

In reaction, as a multimedia designer, I wanted to create a definitive resource containing scientifically accurate information about how to treat a dog in heatstroke.  The result of my research and work was The "CLAW" Process:

See the PDF version of this graphic, ready for printing and sharing, here.

About Jon

I am a dog-loving visualization and graphic designer, writer and creative consultant. My professional bio is here. The most important, joyous job I’ve ever had, was as “dad” to Shayna, the “miracle dog” who helped to save my life after 9/11, and about whom I wrote my first book, “Saved By Shayna: Life Lessons From A Miracle Dog.” Read the Introduction here. See a short video about what made Shayna such an incredibly talented, inspiring and hilarious dog here. I created HeatKills.us (and its predecessor site, HeatKills.org) to help raise awareness of the dangers of leaving a dog in a hot car. Learn about my creation of the HeatKills project here.