Heat Stroke in Dogs: Signs, First Aid, Hot Cars

What is heatstroke in dogs?

Heatstroke is a dangerous rise in body temperature that happens when a dog cannot shed heat as fast as it gains it. The RSPCA Knowledgebase calls it a life-threatening emergency and says that in dogs it can lead to rapid multi-organ failure and has a high mortality rate. Dogs cool down by panting; the RSPCA says flat-faced breeds have a reduced capacity to cool down this way, and that heatstroke is a greater risk in warm or hot, humid environments.

Most affected dogs in UK general practice survived, but not all. A study of 905,543 dogs under veterinary care in the UK in 2016 found 395 confirmed heat-related illness events, and 14.18% of them ended in the dog's death (Hall, Carter and O'Neill, 2020). A follow-up study notes earlier research in which survival fell from over 90% to 43% once dogs progressed from mild or moderate to severe disease (Hall et al, 2022). The RSPCA's advice is to start first aid and seek veterinary attention immediately.

LocalPetFinder is an adoption listings site, not a vet. This page brings together the RSPCA, government pages and published veterinary research, read in November 2026. It is general information, not a substitute for your vet.

What are the signs of heatstroke?

The RSPCA lists these signs. A dog may show a few or many, and they can move quickly from the first column to the second:

Source: RSPCA Knowledgebase, updated 8 May 2023, read 11 November 2026. The grouping into two columns is ours, to make the list easier to scan; the RSPCA lists them together.

Panting after a run is normal. Panting that does not ease when your dog rests in the shade, or comes with any of the signs above, is not. RSPCA South Australia's vet puts it simply: a dog panting excessively should be moved somewhere cool straight away, and any wobbliness, collapse or distress means contacting an emergency vet straight away (RSPCA SA).

What is the first aid for heatstroke?

This is the RSPCA Knowledgebase first aid, quoted in full (updated 8 May 2023, read 11 November 2026):

“If you suspect your dog is suffering from heatstroke, start emergency first aid. Try to cool your dog down by applying room-temperature or cool water to their fur/skin. To maximise heat loss, keep the environment cool (e.g. fan, air-conditioning). Seek veterinary attention immediately.”

That is the whole of it. The RSPCA's steps use room-temperature or cool water and do not mention ice, and we do not add steps the RSPCA does not publish. The first aid does not replace the vet: the last step is to seek veterinary attention immediately.

Which dogs are most at risk?

The RSPCA names these risk factors: body weight (overweight dogs overheat faster), breed (flat-faced breeds have a reduced capacity to cool down by panting), sex (male dogs are more likely to develop heatstroke after exercise), age (very young and very old dogs), a hot or humid environment without shade, water or airflow, too much exercise, and transport. It also notes that the risk is increasing as heatwaves become more frequent.

The biggest study of the question looked at UK dogs in general vet practice. It is not Australian, but it is the clearest breed-level evidence published, and the RSPCA cites it:

Source: Hall, Carter and O'Neill, Scientific Reports, 2020: VetCompass records of 905,543 dogs under primary veterinary care in the UK in 2016, 395 heat-related illness events. Non-designer crossbred dogs were not at significantly different odds from Labradors.

Odds ratios are about relative risk, and heat-related illness was uncommon overall in this UK population (0.04% of dogs in a year). An Australian summer is hotter and longer, so the absolute risk here will differ, but the pattern is consistent with the RSPCA's warning about flat faces, weight and age. A follow-up VetCompass study also found that the majority of cases were triggered by exertion, and that the median air temperature on the days dogs fell ill was 16.9 degrees (Hall et al, 2022). In that UK data, a mild day and a hard run were the everyday pattern.

Why are flat-faced dogs at higher risk?

Because they cannot pant as well. The RSPCA Knowledgebase says brachycephalic dogs, such as pugs, British and French bulldogs and Boston terriers, can have brachycephalic obstructive airway syndrome (BOAS), a lifelong and often progressive breathing problem, and lists exercise and heat intolerance among their health problems. Its heatstroke page adds that flat-faced breeds have a reduced capacity to cool down by panting, and its prevention list includes avoiding high-risk breeds with exaggerated features. The RSPCA also says the snuffling, snoring and snorting these dogs make are signs that breathing is very difficult and distressing for the dog.

RSPCA South Australia's vet advises that more at-risk dogs, such as brachycephalic breeds, should not be walked when it is over 25 degrees (RSPCA SA). Our breed guides go deeper:

• Pug breathing and heat care (Sydney), also for Brisbane and the Gold Coast
• British Bulldog heat and breathing (Sydney), also for Perth and Brisbane
• French Bulldog heat and breathing care (Brisbane), also for Perth
• Boston Terrier breathing and heat care (Sydney)
• Boxer exercise and heat and German Shepherd heat management
• Thick coats: Alaskan Malamute, Bernese Mountain Dog, Saint Bernard and Golden Retriever

Is it illegal to leave a dog in a hot car?

Never leave a dog in a parked car on a warm day, legal or not. The RSPCA says even on an overcast day with the windows down, dogs can overheat and die in a short time. RSPCA Australia says the temperature inside a car can climb to double the outside temperature in a short time, and RSPCA WA says that on a mild 22-degree day the inside of a parked car can rise to over 47 degrees in a matter of minutes, and that tinting, shade and open windows give little or no relief. The VetCompass researchers found that dogs overheated in vehicles were more likely to develop severe disease, because they could not escape the heat (Hall et al, 2022).

The law differs across Australia. Here is what the official page or legislation says in each place, as read on 11 November 2026:

This is general information from the pages linked, not legal advice. For South Australia we found no government hot-car page (searched 11 November 2026), so the reporting advice in that row comes from RSPCA SA; the WA penalty figure is from RSPCA WA, not a government page. Penalties change; check the current legislation in your state. A time or temperature in a law is not a safe allowance: the NSW bill itself says (proposed section 7A(5)) that compliance with the new section is not a defence for an offence against another provision of the Act or the regulations.

If you see a dog in a hot car, call police or the RSPCA in your state straight away and do not break in yourself. RSPCA WA suggests noting the registration and location, asking shopping centre management to page the owner, and watching the dog from a distance until help arrives (RSPCA WA).

How hot is too hot to walk a dog?

No authority publishes one cut-off temperature for every dog, so test the ground and watch your dog. These are the tests the RSPCA publishes:

• The five-second rule. RSPCA Australia: place the back of your hand on the ground for five seconds; if it is too hot for you, it is too hot for your dog. RSPCA WA uses the same five seconds.
• A longer test. RSPCA South Australia's vet suggests bare hands or feet on a sun-exposed surface for 10 seconds (RSPCA SA). The stricter of the two is the safer habit.
• Walk early or late. RSPCA Australia advises early mornings and evenings on hot days. If it stays warm overnight, RSPCA SA's vet suggests a shorter walk than usual.
• It is not just bitumen. The RSPCA Knowledgebase says the ground can be unsafe in warm weather on bare earth and grass too, especially brown grass in sunny, dry spots, and that hot ground adds to the heat a dog is already carrying.
• Higher-risk dogs: flat-faced breeds should not be walked when it is over 25 degrees, according to RSPCA SA's vet.

Shaded bush tracks are cooler underfoot, but RSPCA SA points out they bring snakes and grass seeds. Keep your dog on a lead in scrub and check its paws afterwards: see grass seeds and dogs and snake bite in dogs.

How do I keep my dog cool at home?

• Shade and airflow at all times. The RSPCA says dogs need access to a cool, shaded area with good ventilation at all times.
• More water than you think. RSPCA Australia suggests several water sources in sturdy bowls that are hard to knock over.
• Bring them in. On really hot or humid days, RSPCA Australia suggests bringing pets inside with air-conditioning, fans or open windows. Shade in the yard is not always enough.
• Keep the weight down. Overweight dogs overheat faster and cool less well, says the RSPCA.
• Skip the midday game of fetch. In the UK research most heat illness was triggered by exercise, so play in the cool of the morning or evening.

Adopting a dog that copes with Australian heat

If you live somewhere hot and humid, the honest advice from the RSPCA's own risk list is that a flat-faced breed needs more planning, and some households will be better suited to a longer-nosed dog. That is not a reason to pass over a pug or bulldog in rescue, many of whom need homes; it is a reason to go in prepared with air-conditioning, a walking routine and a vet nearby. Our pug, French Bulldog and British Bulldog guides cover what to ask a rescue or breeder.

Older dogs are also at higher risk in the heat. If you are thinking about adopting a senior dog, plan its summer the same way. For everything else in the first months, see a rescue dog's first weeks and adopting a dog in Australia.

More guides for dog owners

• Flying with a pet in Australia: airline and interstate rules for travelling with a dog or cat.
• Barking dogs and bark collars: the law and the RSPCA position.
• Cat enclosures and catios: for the cat in a dog household.
• Cheap vet care: charity clinics and help with an emergency bill.