If your dog is showing signs of heat exhaustion, start cooling them down immediately with cool (not ice-cold) water and airflow, then get to a veterinarian. A normal canine body temperature sits around 101 to 102.5°F. At 104°F, a dog is in moderate heatstroke territory and needs immediate care. At 106°F, the situation becomes a dire emergency with the potential for organ failure.
Speed matters here. The faster you lower your dog’s body temperature, the better the outcome. Here’s exactly what to do, what to watch for, and what happens after the crisis passes.
Recognizing the Signs Early
Heat exhaustion in dogs progresses quickly, and the early signs can be subtle if you’re not watching for them. The first thing you’ll usually notice is excessive panting that seems heavier or more rapid than normal. Your dog may drool more than usual, and the saliva can appear thick or ropy. They may seem restless or agitated at first, then become lethargic or unsteady on their feet.
As the condition worsens, the gums may turn bright red or, in more severe cases, pale or bluish. Vomiting and diarrhea can develop, sometimes with blood. If your dog becomes disoriented, stumbles, collapses, or loses consciousness, the situation has crossed into full heatstroke. At that point, organ damage may already be underway.
Step-by-Step Cooling at Home
Move your dog to a cool area right away. Indoors with air conditioning is ideal, but shade with a breeze works too. The goal is to stop heat from building and start bringing their core temperature down.
For young, otherwise healthy dogs, cold water immersion is the most effective approach. Fill a tub, kiddie pool, or even a large container with cool water and submerge your dog’s body (keeping the head above water). For older dogs, overweight dogs, or those with known health problems, the Royal Veterinary College recommends an evaporation method instead: pour water of any temperature cooler than your dog over their body and combine it with air movement from a fan, breeze, or air conditioning. The evaporation is what pulls heat away.
If you can’t do either of those, hose your dog down with cool water, focusing on the neck, armpits, and groin where blood vessels sit close to the surface. Placing cool, wet towels on those areas can also help, but swap them frequently since they warm up fast and can actually trap heat against the skin.
One critical point: do not use ice or ice-cold water. It sounds counterintuitive, but extremely cold water causes the blood vessels in the skin to constrict, which actually reduces your dog’s ability to release heat. It can also trigger shivering, which generates more body heat and makes the problem worse.
Offer small amounts of cool water to drink, but don’t force it. A dog that is vomiting or barely conscious should not be made to swallow water.
Getting to the Vet
Heatstroke is classified as an immediate emergency in veterinary triage, on the same level as seizures, collapse, or difficulty breathing. Even if your dog seems to recover after cooling, internal damage may already be developing. The vet visit is not optional.
Begin cooling your dog before you leave for the clinic and continue during the drive. Run the car’s air conditioning on full, place wet towels on the seats, and keep airflow moving over your dog’s body. If someone else can drive, sit with your dog and continue applying cool water.
Stop active cooling once your dog’s temperature drops to around 103°F if you have a rectal thermometer available. Cooling below that point can cause a dangerous rebound where body temperature drops too low.
What Heat Does Inside the Body
Understanding why veterinary care matters even after your dog “looks better” comes down to what prolonged high temperatures do internally. Excessive heat damages blood vessels throughout the body, which can trigger widespread, abnormal blood clotting. That clotting, in turn, can starve organs of blood flow.
The gut lining is particularly vulnerable. Heat reduces blood flow to the intestines and directly injures the cells lining them, allowing bacteria to leak from the gut into the bloodstream. This can cause a body-wide inflammatory response and, in severe cases, multi-organ failure. The liver takes a direct hit from heat as well, and kidney damage from reduced blood flow and muscle breakdown is common. The brain is not spared either: heat can cause brain swelling, neuronal death, and seizures.
These complications don’t always show up immediately. A dog can appear to improve with cooling and then deteriorate hours later as internal damage progresses.
Which Dogs Are Most Vulnerable
Short-muzzled breeds like Pugs, Bulldogs, French Bulldogs, and Boston Terriers face significantly higher risk. Their compressed airways make panting, the primary way dogs cool themselves, far less efficient. A Bulldog can overheat in conditions that a Labrador handles without trouble.
Beyond breed, several other factors raise risk:
- Overweight dogs carry extra insulation and generate more heat during activity
- Older dogs have less efficient circulation and temperature regulation
- Dogs with heart or lung disease can’t increase blood flow to the skin as effectively
- Thick or dark-coated breeds absorb and retain more heat
- Dogs not acclimated to heat, such as those who recently moved to a warmer climate or experience a sudden heat wave
What to Watch for After Treatment
Even after your dog has been treated and seems stable, close monitoring for several hours is essential. Heat injury can rebound or reveal delayed complications. Vomiting and diarrhea are common in the hours following a heat event, and the diarrhea is often bloody.
Watch for small red or purple spots on the skin, gums, or belly (signs of clotting problems), blood in the urine, sudden weakness or collapse, pale gums, rapid breathing, or a return of restlessness and anxiety. Any of these indicate the situation is worsening and requires immediate veterinary attention.
Your vet will likely want to monitor bloodwork over the following 24 to 72 hours to check kidney function, liver enzymes, and clotting ability. Some dogs recover fully within a day. Others, particularly those whose temperature reached 106°F or above, may need several days of intensive monitoring and supportive care.
Preventing Heat Exhaustion
Most cases of canine heat exhaustion are preventable. Exercise your dog during the cooler parts of the day, typically before 8 a.m. and after 6 p.m. in summer. Pavement and asphalt can reach temperatures far above the air temperature, burning paw pads and radiating heat upward into your dog’s body.
Never leave a dog in a parked car, even with windows cracked. Car interiors can reach 120°F within minutes on a warm day. Provide constant access to shade and fresh water when your dog is outdoors. For high-risk breeds, consider limiting outdoor time to brief bathroom breaks on the hottest days and relying on indoor play and mental enrichment instead.
If your dog is exercising and begins panting harder than the activity warrants, stop immediately, move to shade, and offer water. Catching the earliest signs of overheating and responding in that moment is the single most effective thing you can do to prevent heat exhaustion from becoming heatstroke.