black lab experiencing heat stress in a hot environment

We all know it can get dangerously hot out there. You don’t need another reminder to avoid leaving your dog in the car or going for a mid-afternoon jog with them (although I still see this happening, and it still makes my blood boil). But what you do need to know is that heatstroke in dogs can happen faster than you think—and the way you cool your dog down can mean the difference between life and death.

That’s why I brought back Dr. Cynthia Otto, executive director of the Penn Vet Working Dog Center, who is doing groundbreaking, practical research on this very topic. And when I say practical, I mean the kind of information that should be printed on a magnet and slapped on your fridge.

🎧 Catch the full episode on your favorite streaming platform.
📺 Or you can watch it on YouTube

The Shocking Truth About Heatstroke in Dogs

Here’s what really stopped me in my tracks: 50% of dogs who suffer true emergency heatstroke will die. That’s not scare tactics—that’s what the veterinary literature shows. And what’s worse, by the time you’re dealing with visible signs like collapse or disorientation, the damage to your dog’s internal organs—especially their brain—may already be underway.

We talk so much about panting, paw pads, and resting in the shade. But Dr. Otto’s research is reframing the whole conversation: it’s not just about cooling the body—it’s about protecting the brain.

dog experiencing heat stress with tongue out

Photo credit: Shelby Wise

Why Your Dog’s Head Matters Most

Dr. Otto and her team tested multiple field-cooling techniques, mimicking real-world situations: towels around the neck, alcohol on the paw pads (which, spoiler alert, dogs hate), standing in a kiddie pool. Some helped a little, but the most promising technique turned out to be something unexpectedly simple: dunking the dog’s head in water.

Not ice water, not a forced spray from a hose—just cool, room-temperature water that surrounds their skull and, by extension, helps cool the brain. It’s voluntary, effective, and trainable. In fact, her team taught dogs to do it themselves using—you guessed it—string cheese. Drop the treat in a clear container with just enough water to cover it. Increase the water level gradually. Most dogs picked it up in under ten minutes.

It’s like teaching a trick that could save their life.

🎧 Hear how they taught the “Go Fishing” head-dunk technique step-by-step.

📺 Want to see Dr. Otto demonstrate it? Watch the training video.

Know the Signs—and Don’t Wait

series of a dogs progression from none to moderate heat stress

Progressive heat stress from none to moderate. Photo credit: Amritha Mallikarjun

Heatstroke doesn’t look dramatic until it’s critical. Your dog might just have a long, flat tongue hanging out the side of their mouth. Their eyes may squint. Their obedience may waver. These are the early signs. If your dog suddenly flops down and stops responding, it’s already serious.

And don’t assume your dog will regulate themselves. Some dogs—especially working breeds or ball-obsessed retrievers—will run until they drop. They’re not being brave. They’re in danger.

Should You Use a Hose?

Only if your dog likes it. A hose blasting at the head can be aversive—and your dog may never let you try it again. The better bet? Train a voluntary head dunk. Let them choose to cool off.

📺 Watch Dr. Otto explain how this method was discovered and tested.

yellow lab with tongue out experiencing heat stress in a hot environment

Photo credit: Shelby Wise


Don’t Forget Puppies and Seniors

Puppies are more water than body mass, and seniors don’t regulate heat as well. But ironically, it’s those gung-ho, play-until-they-collapse young adult dogs who are most often affected. Dr. Otto urges us to pay attention before they show signs—especially when hiking, playing fetch, or just being outdoors for extended periods.

But What About Brachycephalic Dogs?

If you’ve got a Frenchie, a pug, or a bulldog, you already know they’re at higher risk in the heat. These breeds don’t breathe efficiently (thanks to human vanity and poor breeding practices), and they often struggle to cool themselves even in mild temperatures. Dr. Otto was honest: we haven’t tested the dunking method with brachycephalic dogs yet. But they need even more caution, not less. Don’t wait for panting. Don’t even wait for a hot day. Keep them cool from the start, or better yet, indoors.

Bottom line? Train the dunk. Carry a container. Stock string cheese. And above all, use common sense. If it’s too hot for you barefoot on the pavement or stuck in the car with the windows cracked, it’s too hot for your dog—fur coat and all.

And a huge thank you to Dr. Otto and the AKC Canine Health Foundation, whose research funding is making this life-saving work possible.

— Tracie