Summer heat and dogs: hot pavement, hot cars and heatstroke on walks

Everyone knows not to leave a dog in a hot car, but the bigger summer danger for most dogs is the walk, the run or the game of fetch on a warm day — so the habits that protect your dog are simple: exercise in the cool of the day, test the pavement, carry water, and know how to cool a dog fast.

Dogs don’t die just in hot cars

Using records from 905,543 dogs under UK veterinary care, Hall, Carter and O’Neill (2020) found that exercise was the trigger in 74.2% of heat-related illness events, hot weather alone in 12.9% and being shut in a vehicle in 5.2%. Young male dogs were more likely to overheat during exercise, while older dogs and dogs with breathing problems were more likely to overheat simply from hot weather. Dogs that overheated during exercise were about as likely to die as those overheated in cars.

In a follow-up study, Hall and colleagues (2022) found that the median outdoor temperature on days when dogs developed heat-related illness was only 16.9°C (62°F). Age, bodyweight and the trigger affected how severe the illness was, while age, skull shape and how sick the dog was on arrival affected the risk of death.

Who is most at risk

• Flat-faced (brachycephalic) dogs. A 2022 evidence review by Clark concluded that brachycephalic dogs likely have a higher risk of heat-related illness, and Hall’s 2020 study found higher odds for all three triggers.
• Heavier and overweight dogs, and young, energetic dogs who won’t stop on their own.
• Older dogs and dogs with heart or breathing problems.
• Puppies, who can’t yet regulate their temperature well and rely on you to stop the game.

Walks and play in summer

• Go early or late, and keep walks shorter and slower when it’s warm or humid.
• Choose shade and grass, and let your dog set the pace.
• Bring water and offer it often.
• Stop at the first sign of heavy panting, slowing down, lying down or seeking shade.
• Skip the ball. A dog that loves fetch will keep running long after it should stop.

Hot pavement

Researchers at Washington State University’s College of Veterinary Medicine, drawing on older thermal-burn research, note that in direct sun and without wind, asphalt can reach about 125°F (52°C) when the air is 77°F (25°C), and about 143°F (62°C) when the air is 87°F (31°C). Their advice: press the back of your hand to the pavement — if you can’t keep it there for seven seconds, it’s too hot for your dog. Signs of burned pads include limping, refusing to walk, blistering or peeling pads and licking the feet; burns can take time to show.

Parked cars

The American Veterinary Medical Association (AVMA) reports that the inside of a parked car heats up by about 19°F in 10 minutes, 29°F in 20 minutes and 43°F in an hour, whatever the outside temperature — so on a 70°F day it can be over 110°F inside within an hour. Cracking the windows makes no difference. AVMA’s advice is simple: never leave your pet alone in a parked vehicle, however briefly.

If your dog overheats: cool first, then transport

Hall and colleagues (2023) note that guidance for owners and first responders advises “cool first, transport second”, using cold-water immersion or pouring water on the dog combined with moving air. Yet in their UK study, only about one in five dogs was cooled before being taken to the vet, and the most common method recorded — draping wet towels — is not one of the recommended approaches.

• Move your dog to shade or air conditioning.
• Cool with water: pour or hose cool water over the body, or immerse the dog if it’s safe to do so, and fan it or let air move over it.
• Offer small amounts of water if your dog is alert and can drink.
• Call your vet and go — even if your dog seems to recover.

When to call your veterinarian

• Heavy panting that doesn’t settle with rest and shade.
• Weakness, wobbling, collapse, confusion or seizures.
• Vomiting or diarrhea, especially with blood.
• Bright red, dark or pale gums.
• Limping, blisters or peeling pads after walking on a hot surface.
• If in doubt, call — your vet would rather hear from you early.

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Sources & further reading

1. Hall EJ, Carter AJ, O’Neill DG (2020) — Dogs Don’t Die Just in Hot Cars — Exertional Heat-Related Illness (Heatstroke) Is a Greater Threat to UK Dogs. Animals 10:1324. doi.org
2. Hall EJ, Carter AJ, Chico G, Bradbury J, Gentle LK, Barfield D, O’Neill DG (2022) — Risk Factors for Severe and Fatal Heat-Related Illness in UK Dogs — A VetCompass Study. Veterinary Sciences 9:231. doi.org
3. Hall EJ, Carter AJ, Bradbury J, Beard S, Gilbert S, Barfield D, O’Neill DG (2023) — Cooling Methods Used to Manage Heat-Related Illness in Dogs Presented to Primary Care Veterinary Practices during 2016–2018 in the UK. Veterinary Sciences 10:465. doi.org
4. Clark AE (2022) — Heatstroke and brachycephalic dogs – is there an increased risk? Veterinary Evidence 7(4). doi.org
5. American Veterinary Medical Association — Pets in vehicles. avma.org
6. Washington State University College of Veterinary Medicine (2017) — Protect your pet’s feet from heat, burns. archive.news.wsu.edu

Where evidence is limited, recommendations rest on established practice and expert judgment, and may be updated as knowledge develops. This is general information and does not replace advice from your veterinarian.

Next steps

• Read next: Heatstroke in breeding dogs and puppies.
• Related: A first aid kit and first aid basics for dog owners.
• Return to the guide: For your puppy buyers.