July 18, 2025

Heatstroke in Dogs: First Aid and Prevention Tips for Hot Weather

As the weather warms up, it’s essential to protect your dog from overheating. Overheating to excess can lead to “heatstroke,” a potentially life-threatening condition. Pet owners often take for granted how hard it is for dogs to cool themselves in hot, humid environments. Dogs don’t sweat like we do; instead, they pant and rely on the cooling effects of evaporation off the surface of their tongues to cool them down. In hot, high-humidity environments like NC and SC, evaporation slows, and it makes a dog’s ability to cool down less effective. Each summer, veterinary clinics see an uptick in heatstroke cases, many of which are entirely preventable with the right precautions.

What Is Heatstroke in Dogs?

Heatstroke is a severe and life-threatening condition caused by extreme or prolonged hyperthermia. Hyperthermia simply means an elevation of core body temperature. While a dog’s normal body temperature is around 101-102.5°F (38.3-39.2°C), a temperature exceeding 103°F (39.4°C) is considered abnormal. Heatstroke typically occurs when a dog’s body temperature rises above 40°C (105.8°F).

Why Heatstroke is a Serious Risk for Dogs

Unlike humans, dogs cannot regulate their body temperature efficiently through sweating, as they have a relatively small number of sweat glands located in their footpads. Their primary method of cooling down is panting. When environmental heat or internal heat generation overwhelms their ability to cool effectively, their body temperature can dangerously escalate. If a dog’s body temperature reaches around 107°F to 109°F (41.2°C to 42.7°C), it can lead to multiple organ failure and can be fatal.

Heatstroke is a serious emergency because elevated body temperature causes the release of inflammatory compounds, alters cellular function, denatures proteins and enzymes, and leads to cell death, which can severely damage multiple organ systems like the lungs, heart, kidneys, brain, and blood clotting pathways.

Early Signs of Heatstroke in Dogs

It’s crucial to be aware of the signs that your dog may be suffering from heatstroke. While mild or transient hyperthermia may not be immediately life-threatening, heatstroke is a true emergency accompanied by changes in behavior and mentation.

Key signs to watch for include:

  • Elevated rectal temperature, generally above 40°C (105.8°F) 
  • Excessive panting, increased respiratory effort, and/or loud breathing
  • Altered mental status, lethargy, disorientation, or collapse
  • Dry or sticky gums or hyperemic (bright red) mucous membranes, sometimes with bruising (petechiae)
  • Diarrhea and/or vomiting
  • Seizures

If your dog exhibits any of these symptoms during or after time in the heat, they may be experiencing heatstroke and require immediate care.

What to Do If You Suspect Heatstroke / When to Seek Veterinary Care

If you believe your dog is experiencing heatstroke, this is an immediate medical emergency. Time is of the essence, and swift action can significantly improve their prognosis.

  • Initiate Cooling Immediately, But Safely:
    • Move your dog to a cooler environment.
    • Begin active cooling efforts right away. This means dousing them with lukewarm or cool water (NOT ice water) over their head, stomach, armpits, and feet. Ice water should be avoided, as it can cause peripheral vasoconstriction, which traps heat in the core and hinders effective cooling.
    • Use fans to improve convective heat loss.
    • Do NOT cover your dog with wet cloths as this can prevent evaporative or radiative cooling.
    • Avoid using ice packs and rubbing alcohol as methods for temperature reduction.
  • Contact Your Veterinarian Immediately:
      • While you are initiating cooling measures, call your veterinarian or your nearest emergency veterinary hospital to let them know you are on your way. They will prepare for your arrival.
      • Heatstroke requires aggressive supportive care and careful monitoring for complications like multiple organ failure, including issues with blood clotting (DIC), kidney injury, and brain swelling. As a result, an ER visit is usually required.
  • Transport Your Dog to the Clinic:
    • Continue cooling efforts during transport if possible.
    • Your veterinarian will continue cooling your dog until their rectal temperature reaches a safe range, typically around 39.2°C-39.4°C (103°F-103.5°F), to prevent overcooling and dangerous hypothermia.

The prognosis for heatstroke can vary depending on the severity and duration of hyperthermia and how quickly treatment is initiated. Pets that have experienced heatstroke may be at a higher risk for future episodes. Early recognition and immediate veterinary intervention are crucial for the best chance of recovery.

Think of heatstroke like a pressure cooker. Your dog’s body is designed to release heat (like steam from the cooker), but if the “vent” (panting mechanism) is overwhelmed or blocked, the internal pressure (temperature) builds rapidly, threatening to damage everything inside. Timely intervention is like carefully releasing that pressure before it causes irreversible harm.

If you suspect your dog has overheated or might be showing signs of heatstroke, it’s best to err on the side of caution and bring your dog for evaluation.

At Truss Vet, we’re open 10 AM to 10 PM six days a week (closed Saturdays), with a full medical team ready to treat heat-related emergencies.

How to Prevent Heatstroke in Dogs

Prevention is always the best approach when it comes to heatstroke.

  • Never leave a dog in a car, even for a few minutes. The temperature inside a car can rise rapidly, even on moderately warm days, leading to dangerous heat exposure. Anxiety from being enclosed can worsen the temperature elevation
  • Ensure access to shade and plenty of cool, fresh water at all times, especially outdoors.
  • Avoid vigorous or prolonged exercise during hot temperatures or on hot summer days. This is particularly important in early summer, before your dog has acclimated to the heat
  • Be extra cautious with certain breeds and individuals, as they are at higher risk:
    • Brachycephalic dog breeds (flat-faced dogs like Pugs, Boxers, and Bulldogs) are particularly susceptible due to their restricted airways. For these breeds, heatstroke can occur even when temperatures and humidity are only moderately elevated
    • Obese dogs
    • Pediatric or geriatric animals.
    • Dark-colored and/or long-haired dogs exposed to direct sunlight
    • Dogs that are muzzled, as their ability to pant is restricted
    • Dogs with respiratory abnormalities like laryngeal paralysis
  • Be aware of situations that can lead to excessive heat generation, such as seizures or certain intoxications.
  • Educate yourself and others about heat-related dangers

Truss Vet Is Here When Minutes Matter

During the hot summer months, heatstroke in dogs is one of the most serious—and preventable—conditions we encounter at Truss Vet. Our urgent care clinics provide fast, same-day care when your pet needs it most.

Whether you’re responding to a heat emergency or want help creating a warm-weather safety plan for your dog, we’re here to support you. Visit our locations page to find the Truss Vet clinic nearest you.

Don’t wait until it’s too late. Knowing the signs, taking quick action, and following prevention tips can keep your dog safe, happy, and healthy all summer long.

Need help fast? Walk in or call ahead to your nearest Truss Vet location—we’re ready when your pet needs us.