Sirius, the brightest star in the constellation Canis Major, influenced what many people refer to as the 'dog days of summer'. Although it doesn't have anything to do with temps getting hotter and more sultry, our ancestors once believed it did. That's where this phrase comes from—our earthbound puppers have nothing to do with it! They also don't have the chance to fan themselves with their paws and tell us how warm it is, but they have other ways of letting us know they're heating up.
One clear sign of how hot is too hot for dogs is if your pooch's tongue is hanging long and she's panting a lot. Canine cooling doesn't happen by sweating, as humans will do, but rather through panting: when moisture inside your dog's mouth and on her tongue evaporates, this helps her thermoregulate.
Bonnie Bragdon, DVM, MS, is co-founder and president of the Independent Veterinary Practitioners Association. She says excessive panting is one sign of heat exhaustion. "Others include lowered energy, unwillingness to move or walk, and rising body temperature," she adds. So beware, as unchecked heat exhaustion leads to heatstroke in dogs.
With the tips below, you'll easily avoid putting your pup in the hot seat.
What Temperature Is Too Hot for Dogs?
Bragdon says an essential point to keep in mind is that a dog's temperature is higher than a human's—approximately 101 degrees F to 102.5 degrees F, with an upper level of normal close to 103 degrees F. So ambient air temperature feels hotter to them than it does to us.
The College of Veterinary Medicine at Purdue University explains it this way: "The normal range of temperatures at which dogs and other species can maintain their body temperatures without expending energy to increase heat production or heat loss is called the thermoneutral zone (TNZ), and ranges from...68 degrees F to 86 degrees F for dogs. Outside of the TNZ exist the upper and lower critical temperature zones."
So how hot is too hot for dogs to be outside? Depending on their breed, size, and activity level, probably anything within the higher range of that temperature window and above, as outlined on the chart below.
Illustrations / Caitlin-Marie Miner Ong
Additional factors also determine what temperature is too hot to walk a dog or stay outside for extended periods. For example, not only are dogs affected by ambient air temperature, but also humidity. According to the Humane Society of the United States (HSUS), when animals pant and moisture evaporates, this takes away heat from their bodies. "If the humidity is too high, they're unable to cool themselves and their temperature will skyrocket to dangerous levels very quickly," it notes.
This is especially true of brachycephalic dog breeds. Here are just a few examples:
"These dogs have short snouts, small nostrils, and narrow windpipes, making it difficult for them to expel heat by panting," Bragdon says. To see if your smushed-faced pooch is at risk, review this full list of brachycephalic dogs.
Other physical attributes might make it more challenging for pups to tolerate the heat. If they have heavier hair or wiry fur coats, they could benefit from shorter trims when temperatures rise. However, never shave double-coated breeds, as their fur provides both cooling and sun protection.
Bragdon says other doggos at risk when it's hot include those with chronic obesity, heart disease, and kidney disease, as well as puppies and senior dogs. The chart above provides a risk guide for your special needs furry friend.
How Hot Is Too Hot to Walk Your Dog on Pavement?
Although dogs have durable paw pads, scorching surfaces affect them just as much as they would our bare feet. So to gauge when it's too hot to walk your dog on pavement, simply place your hand on it. If it's not comfortable to leave there for a minute or two, it might burn your dog's paws.
For her own dogs, Bragdon limits physical activity during the heat of the day and mostly walks them in the late evening or early morning, when concrete isn't absorbing the constant blaze of sun and heat. You can also use thick booties or socks for protection—even though they're designed for cold weather, they could make trotting on pavement for a few minutes more comfortable. Also consider a trip to the dog park, where frolicking in the grass and dirt might be cooler.
Manuel Breva Colmeiro / Getty
How To Keep Dogs Safe in Hot Weather
Bragdon says most dogs are capable of staying safe in hot weather if they have enough shade and water. "However, in hot weather, it may be better to visit an indoor doggie daycare facility rather than risk a long hike or run in the park and suffer the consequences of overheating," she says.
Here are some other FAQs regarding hot weather safety tips for dogs.
How hot is too hot to leave a dog in a car?
It's always too hot to leave a dog in the car. The HSUS states, "Not even with the car running and air conditioner on. On a warm day, temperatures inside a vehicle can rise rapidly to dangerous levels. On an 85 degree day, for example, the temperature inside a car with the windows opened slightly can reach 102 degrees within 10 minutes. After 30 minutes, the temperature will reach 120 degrees."
Bragdon says she personally worries about heatstroke once the outdoor temperature climbs into the upper 70s. "Don't leave your dog unattended in a car once the temperature reaches 70 degrees F."
How can I help my dog cool down?
Give her a cool place to lay, such as in front of a fan on a cool wet towel, ceramic tile, or a chilled cooling mat.
And if you don't have a doggie pool, few pups can resist cooling down under a sprinkler!