High temperatures continue rising with each passing year, making summertime increasingly more dangerous for our dogs. Unable to effectively cool down in hot temperatures, dogs are at a much higher risk for heat stroke than people. Despite animal welfare organizations and veterinarians warning the public of how dangerous heat is for our canine companions, many dog owners don’t realize they’ve put their dog in harm’s way until it’s too late. Being a life-threatening condition in which minutes make the difference between life and death, heat stroke is something every dog owner should worry about. It’s not just hot cars and abandoned dogs — every dog can overheat if we are not taking the right precautions.
Natural thermoregulation works like a built-in system for regulating the body’s temperature. To cool down, our bodies produce sweat through the entire surface of the skin. Dogs, however, only sweat through their paw pads, which is a much smaller surface and their paws are in constant contact with the warm ground. This is why the main cooling system dogs rely on is their respiratory system.
They cool down by panting, taking fast breaths with their tongue stretched out, which allows the hot air to evaporate from the tongue and the inner linings of their nose and mouth. They’re essentially breathing out the hot air and inhaling cool air, relying on this mechanism to regulate their body’s temperature in hot weather.
The normal body temperature for dogs is around 101°F (38°C). When the external temperature rises above the natural one, the thermoregulation begins to reach its limit and can’t regulate the inner temperature anymore. This leads to overheating, also known as hyperthermia. It’s crucial to note that the air temperature you see written on your weather app does NOT accurately represent the exact temperature of your dog’s environment!
Enclosed spaces without air conditioning or ventilation quickly heat up to life-threatening temperatures. Exposure to direct sunlight has the same effect. Dogs with black coats, thick coats, and smaller dogs all feel the heat more intensely. The most severe consequence of overheating is heat stroke.
Heat stroke is a life-threatening condition that often has a fatal outcome. It occurs when a dog’s inner temperature rises to 105°F (40.5°C). This high fever, caused by exposure to extreme heat, causes inflammation and damages the central nervous system, leading to irreversible organ, cellular, and neurological damage. Even when survived, heat stroke can end with life-long health complications.
While all dogs are at risk for heat exhaustion in the summer, some breeds have an elevated risk of suffering from overheating. Brachycephalic breeds (flat-faced dogs such as French Bulldog, English Bulldog, Chow Chow, Pug, Boxer, etc.) have extremely short and distorted muzzles, so they’re unable to cool down through panting. Their muzzles are too short for enough hot air to evaporate from their tongue, nose, and mouth.
They often have difficulties breathing all year long because they don’t get the same amount of airflow as breeds with regular muzzles. This becomes a potentially fatal issue during the summer months. Experts and veterinarians agree that flat-faced dogs should be kept out of the heat at all times, as simply sitting in hot temperatures outside is enough for them to suffer heat stroke!
Other breeds with an elevated risk for heat stress are known for their high energy or for performing service jobs. Military, police, assistance, and medical alert dogs all fall into this category. The most affected breeds are Labrador Retrievers, Golden Retrievers, Belgian Malinois, Border Collies, German Shepherds, and English Springer Spaniels. One study found that heat stroke was the second most common traumatic cause of death among US civilian law enforcement dogs, mainly because they were left in hot vehicles.
Weight and age pose additional risks for heat stroke too. Dogs over 22lbs (10kg), as well as dogs overweight by the standard of their breed, are more susceptible to overheating. Very young dogs (under 2 years) are surprisingly more likely to experience heat exhaustion than adult dogs, with the exception of senior dogs (12+ years).
Young dogs are characteristically bursting with energy and don’t know their limits yet, which is why they have the highest chances of exercise-related hyperthermia. In contrast, senior dogs are more prone to environment-related overheating. They are slower and have underlying health issues (such as cardiac or respiratory diseases) that compromise effective thermoregulation.
SAFE ZONE: Generally, you can consider everything under 59°F (15°C) safe. Temperatures between 59-68°F (15-20°C) are considered safe as well, except for brachycephalic breeds.
RISK ZONE: The danger of heat stroke starts elevating when temperatures are between 68-77°F (20-25°C). These temperatures are common in spring and early fall, making dog owners less cautious than in the summer. The main two safety measures in this temperature range are monitoring your dog during exercise and not leaving him in the car.
DANGER ZONE: Temperatures above 77°F (25°C) are dangerous for all dogs! Take all precautions necessary to keep your dog cool; you will find them listed further in this article. Leaving a dog in a car during these temperatures can trigger heat stroke with a fatal outcome in only 15 minutes!! Anything above 77°F puts dogs at immediate risk of heat stroke. Avoid these temperatures with your dog!!!
When we hear about heat stroke in the media, the reports usually focus on dogs left or forgotten in scorching hot cars. But an interesting UK study found that 74% of dogs suffered exercise-related heat stroke! It’s important to clarify that statistics highly depend on the context they apply to — you may remember that law enforcement dogs overheat mostly in hot cars because waiting is a big part of the job. This particular study, though, focused on reviewing 1259 veterinary records of heat exhaustion in 1222 dogs. Of all those cases, 652 were caused by physical activity, with over half of dogs overheating on a walk! The findings of this study challenge the belief that dogs die only in hot cars; heat stroke risks extend far beyond just our vehicles.
This same study also found that heat exhaustion in dogs happens all year round. The numbers start rising in the spring when most dog owners mistakenly perceive the warm weather as safe. It takes time for our dog’s system to acclimate to the warming temperatures if we live in a climate where seasons change every few months. The number of heat stroke cases reaches an absolute peak in July, showing that the height of summer also means the height of heat danger. The chart below illustrates how heat stroke numbers rise and fall throughout the whole year, proving that heat safety needs to be a consistent conversation that isn’t limited to the summer months:
(Image source: Figure 2)
Preventing heat exhaustion is the safest way to avoid heat stroke. Our dogs are involved in almost every aspect of our life, so we're the ones choosing their environment for them. Here are the five most important heat safety tips:
Dogs need to have plenty of cold water available for drinking all day long, all year long. If you have a big property, keep water bowls in multiple places. During the summer months, check the temperature of the water throughout the day to make sure it’s still cold. Always take water with you on walks, regardless of the time of day or length of the walk! I recommend using an insulated thermos so the water can stay cold.
No matter how much our dogs love the sun, exposure to direct sunlight in the peak summer months is a gamble with their life. Too many owners mistakenly believe dogs will move into the shade if they become too hot. Most dogs can’t recognize they’re overheating until it’s too late!!! It’s our responsibility to monitor them and keep them in a cool place. Outdoors, natural shade is the best option. Indoors, air conditioning or fans are a must.
Warm weather that begins in spring calls for extra caution when it comes to exercise. Aside from providing cold water and a shaded path, lower the intensity of physical activity on sunny days, give your dog several breaks, and pay close attention to his panting. In the summer, only take walks in the morning and evening. Avoid taking mid-day or afternoon walks in the scorching heat. From your perspective, it’s just a short walk. From your dog’s perspective, it’s 15 minutes in an oven!
A better option is indoor mental enrichment (nose work, puzzle toys, frozen kongs, etc.) in an air-conditioned or well-ventilated space. It’s reasonable to expect that our dogs will still need a bathroom break or two during the day, so I highly recommend investing in a good cooling vest that your dog can wear on those occasions. Look for vests that cool down your dog’s neck, chest, and abdomen!
You think you’re only running into the store for two things, you’ll leave the window cracked open, and it doesn’t even seem that hot. Please think twice. Summer temperatures rise to a fatal point in an enclosed space within minutes. The same goes for unexpectedly warm days of spring and fall — a very significant number of dogs experience heat stroke in March, April, May, and September. Leave your dog at home when you have to run errands, or ask a friend to watch him while you’re away for the grocery store trip. Some stores allow dogs to enter, so check where you can bring him along!
Avoid long car journeys on hot days if you don’t have air conditioning. If you have it, allow your dog some time to acclimate before moving him from a cold vehicle to the hot outdoors. If you're flying and checking your dog as cargo, book an early morning or a late evening flight and avoid flying during heat waves altogether. Warn the airport staff that a dog is traveling with you, and be 10000% certain they are not leaving him out in the heat even for a few minutes! You should also look up vet clinics in the area where you're traveling to and save the numbers on your phone. Better safe than sorry!
Despite taking all precautions, heat stroke can still come as a surprise. Recognizing the first signs and knowing how to respond in the moment can save your dog’s life. Overheating is a spectrum; the sooner you notice it, the higher chances for your dog’s full recovery. The signs of heat stroke include:
- Excessive panting. Often the first and most obvious sign of heat stress in dogs, but can easily be missed because panting is generally normal. Excessive panting can be recognized by quick and shallow breaths with the tongue stretched out very far and possibly curling upwards.
- Hypersalivation. Excessive drooling with thick or foamy drool.
- Color changes of the tongue and gums to red, bluish-purple, pale, or gray.
- Racing heartbeat.
- Lethargy and shaking. Weak limbs, difficulty walking and standing up, as if their legs can’t hold them anymore.
- High fever. Without a thermometer, look for a dry nose that is hot to the touch, as well as very hot limbs, ears, and abdomen.
- Mental disorientation.
- Vomiting and diarrhea.
- Collapse. A complete loss of consciousness and responsiveness.
If you notice ANY of these signs or suspect that your dog is suffering from heat exhaustion, call an emergency vet IMMEDIATELY. Heat stroke has an extremely fast progression, so once again, think in terms of minutes. As you’re waiting for veterinary care, your only focus should be cooling down your dog as fast as you can. The fastest and safest way to do this is:
- Immediately remove your dog from the source of heat. Move him into the shade, out of direct sunlight, out of a hot space.
- Slowly pour cold water over your dog’s limbs, neck, and abdomen. Do NOT use ice cold water or submerge your dog in an icy bath!!! That could further shock the system and result in hypothermia.
- Apply wet and cold cloths to the limbs, neck, and abdomen. Replace them with new ones as soon as they stop being cold!
- Use a fan, air conditioning, a cooling vest, or a cooling mat to bring down your dog’s temperature. If possible, place him on a cold surface in a ventilated, breezy space.
- Encourage (but don’t force) your dog to drink cold water.
- Keep your dog calm and safe. In the face of extreme heat and disorientation, some dogs will experience panic. If you notice your dog getting restless and panicky, speak to him in a calm voice and take measures so that he can’t escape (close the gate, get a leash, ask a friend to hold him, etc.)
The goal is to lower your dog’s temperature and get him to the vet as fast as you can. You still need to seek veterinary care even if your dog cools down and regains his strength. Overheated dogs can die hours or days later!!! Hyperthermia causes serious inflammation that attacks the dog’s vital functions, which is why clinical assessment and possibly treatment are urgent in any case of overheating. Remember that prevention is always the safest bet and if you have any fellow dog-loving friends, be sure to share this article with them!
Hall, J. Emily. Carter, J. Anne. O’Neill, G. Dan. “Dogs Don’t Die Just in Hot Cars—Exertional Heat-Related Illness (Heatstroke) Is a Greater Threat to UK Dogs.” PubMed, 31/07/2020.
Romanucci, Mariarita. Della Salda, Leonardo. “Pathophysiology and pathological findings of heatstroke in dogs.” PubMed, 09/01/2013.
“Heat Stress Injury Prevention + Care.” VCA Northwest Veterinary Specialists.
Luna’s passion for learning about canine psychology and behavior began when she adopted a severely reactive puppy from a local shelter. She is now a big advocate for positive reinforcement and compassionate training. As a writer, she strives to spotlight the topics that fly under the radar and be the voice for all who cannot speak for themselves.