How to Prevent and Treat Heat Stroke in Your Dog

Most dog owners picture heat stroke happening one way: a dog left in a hot car. But that's not actually where most cases come from. A large-scale UK veterinary study tracking over 900,000 dogs found that exercise, regular walks, hikes, fetch in the yard, caused 74% of heat stroke cases. Hot weather alone accounted for 13%. Cars made up just 5%.

In other words, the dog most at risk of heat stroke isn't the one left behind. It's the one out enjoying the day with you.

That's not meant to scare you off summer walks. It's meant to help you actually protect your dog, because the real risk looks different than most of us assume. Dogs can't cool themselves the way we do. They have very limited sweat glands (just in their paw pads) and rely almost entirely on panting to bring their body temperature down. Panting works a lot less well once humidity climbs, and it barely works at all for flat-faced breeds.

⚠️ IMPORTANT: If you suspect your dog is suffering from heat stroke, start cooling them down and contact a vet immediately.

Here's everything you need to know about heat stroke in dogs: what it actually is, the early signs to watch for, who's most at risk, and exactly what to do if it happens.

Jump Ahead: How to Prevent and Treat Heat Stroke in Your Dog

Key Takeaways

• Exercise, not hot cars, causes the majority of heat stroke cases in dogs. Ordinary walks and play sessions are the biggest culprit.
• Heat stroke has a real fatality rate, roughly 1 in 7 dogs who develop it don't survive, so prevention matters more than knowing how to react.
• Certain breeds face dramatically higher risk. Some flat-faced and thick-coated breeds are up to 17 times more likely to develop heat stroke than a Labrador.
• "Cool first, transport second" is the expert-recommended order of operations. How you cool your dog in the first few minutes matters as much as getting to the vet.
• Even a day that doesn't feel scorching to you can be dangerous for your dog, especially if it's humid or your dog isn't used to the heat yet.

What Is Heat Stroke? (And How It's Different From Heat Exhaustion and Heat Stress)

Heat-related illness in dogs sits on a spectrum, and it helps to know where your dog is on it so you can respond appropriately.

In this chart, see how temperature's relate to risk level with your dog, as well as what to do when temperatures reach these levels. This range is from below 70 degrees, which is considered safe for dogs, to 95+ degrees, which is very dangerous.

Heat stress is the early warning stage

At this stage, your dog is just starting to overheat. You'll usually see increased thirst, panting, and a dog who starts hunting for shade on their own. If you take a break and let them cool down, they typically bounce back fast with no medical care needed.

Heat exhaustion is the middle ground

This is the stage between "starting to overheat" and a true medical emergency. Your dog's body is struggling to keep up, even though they haven't crossed into heat stroke territory yet. This is your cue to stop the activity and start cooling them down immediately.

Heat stroke is the medical emergency

Heat stroke means your dog's core body temperature has climbed above 104°F, and their body can no longer bring it back down on its own. At this point, the heat can damage vital organs if your dog doesn't cool down fast. This is always a "call the vet now" situation, not a "wait and see."

Signs of Heat Stroke in Dogs

Heat stroke can start subtle and escalate fast, which is exactly why it catches so many owners off guard. Since your dog can't tell you they're overheating, it's on you to read their body language and catch it early.

Early signs to watch for:

• Heavy or constant panting, especially if it doesn't slow down even when your dog stops moving
• Excessive drooling
• Bright red gums or tongue (a sign of increased blood flow from rising body heat)
• Restlessness, pacing, or actively seeking shade or water
• Rapid or labored breathing

Signs of a medical emergency, get to a vet immediately:

• Weakness, wobbliness, or collapse
• Vomiting or diarrhea
• Confusion or disorientation, especially if your dog seems unresponsive to their name or cues they usually know
• Seizures or tremors
• Gums that shift from bright red to pale, blue, or gray (this signals the condition is getting worse)

If your dog hits any of the emergency-level signs, don't wait to see if they improve on their own. Start cooling them down and get to a vet right away.

What Actually Causes Heat Stroke in Dogs (It's Not Just Hot Cars)

Here's the breakdown from that same VetCompass study of UK veterinary records:

• Exercise: 74% of cases. Walks, hikes, fetch, off-leash play, anything that gets your dog's heart rate up in warm conditions.
• Hot weather alone: 13% of cases. No exercise required. Just sitting outside on a hot, humid day can be enough for at-risk dogs.
• Cars and travel: 5% of cases. Still real, still preventable, but a smaller share than most people assume.

The rest comes down to a mix of individual factors, which we'll get into next.

A few things make this worse. Humidity is a big one. Dogs cool down almost entirely through panting, and panting works by evaporating moisture off their tongue and airway. When the air is already saturated with moisture, that evaporation slows way down, so a humid 80°F day can be more dangerous than a dry 90°F one.

Your dog's acclimation matters too. A dog who's spent the winter mostly indoors and suddenly gets a long hike on the season's first hot weekend is at higher risk than a dog who's had weeks to adjust gradually.

Which Dogs Are at Highest Risk

Every dog can get heat stroke. But research consistently shows some dogs are carrying a much heavier risk than others, and knowing where your dog falls matters for how careful you need to be.

Compared to Labrador Retrievers (used as the baseline in the VetCompass breed study), these breeds showed a significantly higher risk of heat stroke:

• Chow Chow: 17 times more likely
• Bulldog: 14 times more likely
• French Bulldog: 6 times more likely
• French Mastiff: 5 times more likely
• Greyhound: 4 times more likely
• Cavalier King Charles Spaniel: 3 times more likely
• Pug: 3 times more likely
• English Springer Spaniel: 3 times more likely
• Golden Retriever: 3 times more likely

A few patterns explain most of that risk:

Brachycephalic (flat-faced) breeds struggle to pant efficiently because of their airway structure. That includes Bulldogs, French Bulldogs, Pugs, and Boston Terriers. Research shows flat-faced dogs are about twice as likely to develop heat stroke as dogs with an average muzzle length.

Thick, double-coated breeds like Chow Chows and Golden Retrievers trap heat close to the body, working against them the same way a winter coat would on a hot day.

Bigger, heavier dogs run higher risk too. Giant breeds over 110 lbs were three times more likely to develop heat stroke, and this applies to both large-breed dogs and dogs carrying extra weight for their frame.

Age matters. Dogs over two are already at increased risk, and senior dogs (12+) face the highest risk of any age group, largely because older dogs have reduced cardiovascular and respiratory function and can't dissipate heat as efficiently.

None of this means other breeds are in the clear. It means these dogs need extra caution, and their owners should treat "it's a warm day" as a real planning factor, not background noise.

How to Prevent Heat Stroke in Dogs

Now that you understand what heat stroke is and how it affects all dogs, let's talk about how to prevent it in your own pet.

Know your dog's specific risk factors

Before anything else, get honest about where your dog lands. Are they brachycephalic? Getting up there in age? Carrying extra weight? A dog who checks multiple boxes needs a more conservative approach than a young, lean, average-muzzled dog.

Time your outings around the heat, not around your schedule

Early morning and evening are almost always cooler than midday, even on days that don't feel that hot yet. If you're in the middle of a heat wave with no cool window at all, swap outdoor time for indoor enrichment or mental exercise instead. Your dog's brain gets tired too, and it doesn't come with a heat stroke risk.

Not sure what temperature is actually too much for your dog? We've got a full breakdown of how hot is too hot to walk a dog that accounts for humidity, pavement temp, and your dog's individual risk factors.

Treat water like it's non-negotiable

Fresh water should be available at all times, and that includes days that feel mild to you. Heat stroke doesn't require a heat wave. A humid 75°F afternoon can be enough to catch an unacclimated or at-risk dog off guard.

Give hot pavement a hard pass

Asphalt holds heat well above the air temperature. Press the back of your hand to the pavement for ten seconds. If it's too hot for you, it's too hot for their paws.

Find cooler ways to burn off energy

Since exercise is behind the majority of heat stroke cases, one of the best things you can do isn't to stop exercising your dog. It's to change how they get that energy out.

Water is one of the best tools you have here. Swimming works muscles hard without spiking body temperature the way running does, and it doubles as active cooling. If your dog's new to it, here's how to teach your dog to swim, and if you're wondering where your dog can go swimming near you, that's worth a look before the next heat wave hits.

🐾 Skip the crowded public pool lines and give your dog a private place to cool off. Book a Sniffspot pool near you →

Never, ever leave your dog in a parked car

Even with windows cracked. Even "just for a minute." A car's interior temperature climbs fast, and limited airflow in a confined space pushes core body temperature to dangerous levels quickly, regardless of how mild it feels outside.

Watch your dog like it's your job, because it is

Know the early signs from the section above, and act the moment you see them. The dogs who recover fastest are almost always the ones whose owners caught it early.

🐾 Give your dog room to play and cool off without the chaos of a crowded park. Find a private Sniffspot near you →

How to Treat Heat Stroke in Dogs

If you suspect your dog is heading into heat stroke, the order you do things in actually matters. Veterinary researchers at the Royal Veterinary College put it simply: cool first, transport second. Cooling your dog down before and during the drive to the vet makes a real difference in outcomes, so don't skip straight to the car.

Start cooling immediately

• Move your dog to shade or, ideally, an air-conditioned space right away.
• Apply cool (not ice-cold) water to their body, focusing on the neck, head, belly, and paw pads.
• Point a fan at them while they're wet to speed up evaporative cooling.
• Offer small sips of fresh water if they're able to drink on their own. Don't force it.

Skip the ice water and ice packs. Extremely cold water can constrict blood vessels near the skin's surface, which actually traps heat inside instead of releasing it, and can cause shivering that generates even more heat. Cool and lukewarm water work faster and safer than ice-cold.

Get to a vet, even if your dog seems to bounce back

Heat stroke is a genuine medical emergency, and it can cause internal organ damage that isn't visible from the outside. A dog who seems fine twenty minutes later can still be dealing with damage that needs monitoring. Your vet may recommend IV fluids, bloodwork, or observation depending on how severe the episode was.

Don't skip this step because your dog "seems okay now." Seeming okay and being okay aren't always the same thing after a heat stroke episode.

Frequently Asked Questions: Heat Stroke in Dogs

Let's take a look at some of the most frequently asked questions about heat stroke in dogs.

The Bottom Line on Dog Heat Stroke

Heat stroke isn't just a hot-car problem, it's a during-your-normal-walk problem, which is exactly why so many cases catch owners off guard. The good news is that most of it is preventable once you know what actually drives the risk: exertion, heat, humidity, and your dog's individual factors like breed, age, and weight.

Know your dog's risk level, time your outings around the real heat of the day (not just the calendar), keep water and shade non-negotiable, and watch for the early signs before they become an emergency. And when in doubt, cool first, get to the vet second.

🐾 Want a cooler, calmer way to let your dog burn off energy this summer? Find a private Sniffspot near you →

At Sniffspot, all of our posts are vetted by training and vetrinary professionals. This guide was reviewed by Shannon Finch, AnimalKind Training, as well as Elisa Quinn, CVT, SEA Island Animal Clinic.

Sources:

• VetCompass/RVC study on heat-related illness risk factors in UK dogs
• RVC news release on exercise as the leading trigger of canine heatstroke
• The Conversation, breed-specific heatstroke risk research by RVC epidemiologists
• Cornell Riney Canine Health Center Summer Heat Safety Tips for Dogs