Hot summer days can mean more walks, outdoor adventures, and time in the backyard with your dog. But rising temperatures also bring a serious risk every dog owner should understand: heatstroke.
Dogs don't regulate body temperature the same way humans do. Their primary cooling mechanism is panting, with only limited sweating through their paw pads. When environmental heat, humidity, or strenuous activity overwhelms their ability to cool themselves, body temperature can rise dangerously fast.
Heatstroke isn't simply a dog feeling uncomfortable in hot weather. It's a life-threatening medical emergency that can damage the kidneys and other organs, cause blood-clotting abnormalities and shock, and potentially lead to death.
Recognizing the warning signs early can make a critical difference.
In this guide, you'll learn the signs of heatstroke in dogs, which dogs are most vulnerable, what to do if your dog begins overheating, and how to reduce the risk in the first place.
Important: If you suspect your dog has heatstroke, contact a veterinarian or emergency veterinary hospital immediately. Do not wait for symptoms to disappear on their own.
What Is Heatstroke in Dogs?
A dog's normal body temperature is approximately 100.5°F to 102.5°F (38.1°C to 39.2°C). Cornell University College of Veterinary Medicine describes heatstroke as occurring when a dog can no longer regulate its body temperature and it rises to approximately 105°F (40.6°C) or higher.
Heatstroke can happen when a dog is exposed to a hot or humid environment, exercises too intensely in warm conditions, or is confined somewhere without adequate ventilation.
Common situations include:
- Exercising during hot or humid weather
- Staying outside without adequate shade or water
- Being left inside a parked vehicle
- Spending time in a poorly ventilated enclosed space
- Exercising too intensely without sufficient rest
- Remaining exposed to direct sunlight for extended periods
Humidity matters, too. Panting cools a dog partly through evaporation, and high humidity makes that process less effective.
One of the biggest dangers is how quickly the situation can progress.
A dog may initially appear simply hot and tired before developing increasingly serious symptoms.
That's why owners should recognize the early warning signs, rather than waiting for collapse or severe distress.
Signs and Symptoms of Heatstroke in Dogs
Not every panting dog has heatstroke. Panting after exercise or during warm weather is a normal cooling response.
The concern begins when panting becomes unusually heavy or frantic, doesn't improve with rest, or appears alongside other symptoms.
Early signs of overheating
Watch for:
- Heavy or excessive panting
- Rapid breathing
- Excessive drooling or thick saliva
- Bright-red gums or tongue
- Seeking shade
- Restlessness or agitation
- Reluctance to continue walking or playing
- Skin that feels unusually hot
- Increased heart rate
- Weakness or difficulty maintaining balance
These can be warning signs that your dog's cooling mechanisms are struggling.
If your dog is panting excessively at times when heat isn't an obvious explanation, our related guide [Why Is My Dog Panting So Much at Night? Causes & Solutions] explains several other possible causes.
Signs heatstroke may be becoming severe
As overheating progresses, symptoms can become much more serious.
Watch for:
- Vomiting
- Diarrhea, potentially bloody
- Difficulty breathing
- Severe weakness
- Confusion or disorientation
- Loss of coordination
- Muscle tremors
- Pale, gray, blue, or purple gums
- Seizures
- Collapse
- Loss of consciousness
These symptoms require immediate veterinary attention. Cornell specifically identifies difficulty breathing, bloody diarrhea, vomiting, weakness, confusion, seizures, and collapse as signs requiring immediate transport to a veterinary hospital.
Do not wait to see whether your dog improves overnight or after resting.
Even when a dog appears better after cooling, internal organ damage may not be immediately visible, so veterinary evaluation remains important.
Which Dogs Are Most at Risk of Heatstroke?
Every dog can develop heatstroke.
However, some dogs have a harder time regulating their body temperature and require additional precautions.
Short-nosed breeds
Brachycephalic, or short-muzzled, dogs cannot cool themselves through panting as efficiently as many longer-nosed breeds.
Examples include:
- Bulldogs
- French Bulldogs
- Pugs
- Boston Terriers
- Boxers
These dogs can be particularly vulnerable during hot and humid weather.
Senior and overweight dogs
Older dogs and overweight dogs are also at increased risk.
Age, reduced mobility, and excess body weight can make coping with high temperatures more difficult.
Dogs with medical conditions
Dogs with underlying respiratory or cardiovascular conditions may be more susceptible to heat-related problems.
Cornell identifies respiratory and cardiac disorders—including laryngeal paralysis and heart disease—as risk factors.
Thick- or dark-coated dogs
Dogs with thick or dark coats can also face increased risk in hot conditions. Extra attention to temperature, shade, hydration, exercise intensity, and recovery time is sensible during warm weather.
Regardless of breed, don't assume that a young, athletic, healthy dog is immune.
An enthusiastic dog may continue running, hiking, or playing even as their body temperature rises.
Owners need to set the limits.
What to Do If You Suspect Heatstroke
Heatstroke is an emergency, so the goal is to begin safe cooling while arranging immediate veterinary care.
1 Move your dog out of the heat
Immediately stop exercise and move your dog into shade, an air-conditioned building, or another cool, well-ventilated environment.
2 Contact a veterinarian
Call your veterinarian or the nearest emergency veterinary hospital and explain what happened.
Veterinary treatment may be necessary even if your dog begins appearing better.
3 Begin cooling with cool water
Wet your dog with cool—not ice-cold—water.
Focus on getting water down to the skin rather than simply wetting the surface of a thick coat. Cornell recommends cool water combined with airflow from a fan to help lower body temperature.
4 Use airflow
Place your dog in front of a fan or use air conditioning during transport when available.
Airflow helps promote evaporative cooling.
5 Offer water if your dog is alert
If your dog is conscious, alert, and able to drink normally, offer access to water.
Don't delay veterinary treatment while trying home remedies.
What should you avoid?
Avoid assuming that colder is always better.
AKC's current heatstroke guidance recommends tepid or cool water rather than extremely cold water and emphasizes prompt transport to a veterinarian.
Most importantly, don't wait until your dog collapses before taking action.
Early heavy panting, excessive drooling, weakness, or abnormal behavior during heat exposure should be treated as warning signs.
How to Prevent Heatstroke in Dogs
Preventing heatstroke is much easier than treating it.
A few adjustments to your dog's summer routine can significantly reduce unnecessary heat exposure.
Schedule walks for cooler hours
During hot weather, choose early mornings or later evenings rather than the hottest part of the day.
Always consider humidity as well as air temperature.
Keep fresh water available
Provide access to clean drinking water at home and bring enough water for your dog during walks, hikes, road trips, and outdoor activities.
Provide shade and ventilation
If your dog spends time outdoors, make sure they can move into a shaded, well-ventilated area.
Never rely on a small patch of shade remaining in the same place throughout the day.
Never leave your dog in a parked vehicle
A parked vehicle can become dangerously hot very quickly.
Leaving windows partially open doesn't make a hot car safe for a dog. Cornell identifies being left in a car as one of the common circumstances in which dogs develop heatstroke.
Pay attention to hot pavement
Summer heat isn't only about air temperature.
Hot pavement can injure paw pads and can also contribute to increasing a dog's body temperature.
For more information, read our [How to Protect Your Dog's Paws from Hot Pavement] guide.
Know your individual dog's limits
A French Bulldog, senior dog, overweight dog, or dog with heart or respiratory problems may need much stricter activity limits than a healthy adult dog.
Don't base exercise decisions only on how eager your dog appears to be.
Your dog doesn't need to collapse to be too hot.
Heavy panting, seeking shade, excessive drooling, reluctance to continue exercising, or unusual weakness are reasons to stop the activity and move your dog somewhere cool.
Recognizing those early signals—and acting before they become an emergency—is one of the most important summer safety skills a dog owner can have.
❓Frequently Asked Questions
What are the first signs of heatstroke in dogs?
Early warning signs can include heavy panting, excessive drooling, seeking shade, restlessness, reluctance to continue exercising, and bright-red gums or tongue. Symptoms can progress to vomiting, weakness, confusion, seizures, or collapse.
What temperature is considered heatstroke in a dog?
A dog's normal body temperature is roughly 100.5°F–102.5°F. Cornell states that heatstroke occurs when the dog cannot regulate its temperature and it rises to around 105°F or higher.
Can a dog recover from heatstroke?
Dogs can recover, particularly when overheating is recognized and treated promptly. However, heatstroke can cause serious internal organ damage, and a dog that appears better after cooling may still require veterinary evaluation.
Should I use ice-cold water on a dog with heatstroke?
Current veterinary guidance favors cool or tepid water rather than extremely cold water, together with airflow and immediate veterinary care.
Can dogs get heatstroke inside the house?
Yes. A dog can overheat indoors if the environment becomes excessively hot or poorly ventilated, particularly if air conditioning fails or the dog is already at higher risk. Heatstroke isn't limited to outdoor activity.