How Hot Is Too Hot for a Dog in the Car?

If you think you're doing your dog a favor by bringing him with you on hot summer days, think again.

The inside of the car heats up more quickly than you think, to levels that are dangerous for most dogs.

Plymouth-Canton Patch editor John McKay conducted a non-scientific experiment in mid-July, leaving a thermometer in his car on a typical 90-degree summer day. Upon opening the package, the thermometer was at about 70 degrees — about the temperature of the store from which it was bought.

After driving down the road for about five minutes to without air conditioning, but with all the car's windows open, the temperature reading had hit 100 degrees. 

After a five minute trip into the Dunkin' Donuts, the thermometer inside the car — with windows left cracked — had maxed out at 120 degrees.

Leaving the thermometer inside an unattended car for about 30 minutes produced the most unusual results: The temperature gauge had soared well past the 120-degree mark, circling around toward the 60-below-zero reading.

Dogs struggle to release body heat 

While dogs have higher body temperatures than we do — typically between 101 and 102.5 degrees, according to Kevin Roose from in Plymouth — the only way they can release heat is through their mouths and the pads of their paws.

Like people, different dogs can tolerate different levels of heat. Older dogs are more susceptible to heat stroke, as are dogs with short noses (pugs, Pekingeses, etc.), dogs with dark coats, and of course, dogs with thick coats. Also, dogs who are overweight or in poor general health.

"With most dogs, if you look at their tongue and look at their gums, it's a nice pink color," Roose said. "When the body temperature goes way up, it gets brick red. Very, very dark, bright red."

Roose said another danger posed to dogs is hot asphalt and sidewalks.

"Take your shoe off and stand on the pavement," Roose said. "If you can't stand there, your dog won't want to."

Roose said dogs on hot surfaces often struggle to find shade.

"It's very, very uncomfortable," he said. 

Additionally, he said, the heat can cause damage to the pads on your pet's feet.

Vyvian Gorbea of recommended timing your dog's walks in the early morning and late afternoon, when temperatures can cool down and walking surfaces aren't as hot.

Keeping your dog cool is key

While some of the scorching climates this summer have come back down to Earth, hot days still remain this summer. Roose said it's key to keep your dog cool and hydrated.

For those without air conditioning, Roose recommends plenty of ventilation and fresh water. He also recommended investing in a kiddie pool for dogs who prefer the outdoors and are comfortable with water.

Dogs also are sensitive to so-called ozone action days, where pollutant levels are high.

The safest bet is to keep your dog inside on those days, Gorbea said.

"If we have problems breathing, they can too," she said.