1500 words-ish, probably somewhere around a ten minute read. Take the time and read the potentially life-saving info.
I’ve been around dog-internet for a really long time. I was around and first interacting with training/behaviour colleagues via LISTSERVE and Yahoo! Lists…yep, that long ago…
Back in those days, I truly believed that our collaborations online, via this new and developing social media, could change things. Really change things. Naively I, and many wonderful colleagues, really went to bat promoting reinforcement based approaches while lambasting aversive approaches; our main adversary at that time, was the emerging giant, Cesar Milan, and all he stood for.
There was backlash, and arguments, and it was so often heated. But all it served was to create more and more polarisation and the promotion of not-very-scientific arguing. I’m not proud of it, I recognise the good bits and the dogma. And I would probably do it differently if I had the chance for a do-over.
But despite all that, some of the worst backlash I have ever been on the receiving end of is when I have shared the most current, up-to-date, evidence-based information about first aid for HRI (heat related illness). Sheesh.
Actual lifesaving information about what to do in an emergency. And HRI is an emergency. We have minutes to make decisions, to do what needs to be done, and to get the dog to clinic.
Jump to:
- Heat Related Illness (HRI) details & overview
- Recognise when to take care!
- Stop the heating!
- This is an emergency!
- Share evidence based information.
- Get them Wet. Get them to the Vet.
What do you need to know?
Heat Related Illness (HRI), is a dangerous rise in body temperature that the body’s normal temperature regulating systems can’t accommodate. HRI leads to hyperthermia and thermal tissue damage. (Bouchama & Knochel 2002)
Less than half the dogs who develop severe HRI survive (Hall et al, 2021), but with early intervention lower case fatality rates have been recorded, e.g. 14% in Hall et al, 2020.
In dogs, HRI is most commonly caused by exertion in warm ambient temperatures. Contrary to popular belief, confinement in vehicles accounts for a relatively small proportion of HRI cases. (See Hall et al, 2020)
That’s not to suggest that you should confine dogs to a hot vehicle (!), but that the emphasis in popular media may cause bias. We must promote an understanding of the effects of exertion too. (See the Dogs Don’t Just Die in Hot Cars campaign)
Dogs taken from hot cars showing signs of HRI, were more likely to develop severe signs (Hall et al, 2022). Being left in hot car is very dangerous, but not the only risk we should emphasise!
The differences in successful outcomes is thought to be associated with getting help sooner. Usually, the dog has been left in the car alone so an owner may not get back to them until HRI has progressed, while humans may be able to get help quicker when out with their dogs exercising (Hall et al, 2022). The bottom line is that more dogs die from HRI after exertion (Hall et al, 2020).
In London, dogs were found to be more likely to be confined to hot buildings and Hall et al, 2022, showed that the number of HRI cases relating to hot-building confinement was doubled there. This is likely replicated in other urbanised environments particularly due to the way concrete structures & distribution of buildings hold heat along with a lack of trees, or places where dogs are confined indoors in warm places for long periods, during mild and warm weather.
Recognise when to take care!
This dog, in this clip, shows excessive panting. Note their posture, raised head, extended tongue and the panting – this posture and panting shows the body trying to get more air. Stop the heating!
First aid now!
Dogs don’t regulate their behaviour well when stressed and wound up, which may include excitement and exertion. This means they will continue to go-go-go even when uncomfortably hot or in pain.
It’s important to note that exertion related heat distress occurs all year round, while confinement in vehicles accounts for cases in the Spring/Summer mainly. (The Hall et al, works are based in the UK, so you would imagine similar weather/conditions in Ireland.)
Hall et al, 2022, found that the maximum ambient temperature on days with HRI reports was just 16.9C (about 62F). This shows that we must monitor our dogs’ exertion and thermal comfort, even on mild days.
There was even one case of exertional HRI recorded on a 3.3C day!
And it gets interesting when we consider how dogs in hotter climates fare. Bruchim et al, 2008, looked at cases of HRI in Israel. They found that about 85% of dogs presenting at the veterinary hospital had developed HRI signs on 24C days.
‘Heat waves’ may be particularly risky as dogs will take about 4-6 weeks to acclimate to changes in temperature.
And how ambient temperature is measured, recorded and reported may also mislead. For example, weather station temperature, often what’s reported on the news, will be taken in the shade. Your dog playing in your garden in the sun may experience much greater temperatures.
With increases in the use of artificial grass, especially in homes with pets, there are plenty of reports of how hot that surface becomes. If you are taking care with the temperature of pavements your dog walks on, consider also the surfaces at home.
Stop the heating!
Our tendency is to think of cooling, and most dangerously, gradual cooling for dogs with HRI. Instead, let’s start thinking in terms of stopping the heating first.
Contrary to popular belief, dogs do sweat but their main form of cooling, at higher ambient temperatures, is panting, and this puts strain on the body and produces heat. (How do dogs regulate their body temperature? from Dr Marlin)
There really is little evidence to suggest that using cold or ice water slows cooling. While ice water may cause vasoconstriction (narrowing of blood vessels), this is unlikely to have an impact on cooling when the dog is overheating, as they are not using radiation of heat, from the skin, to cool the body efficiently.
Cold tap water (under ~15C), poured over the dog likely provides efficient cooling, based on the limited evidence from research (Magazanik et al, 1980). Although much colder water was shown to be similarly effective, in an emergency situation, it’s probably going to be more efficient to find tap water; this is urgent so we don’t want people going to the trouble of finding icy water!
Move the dog to a cooler area and place them on wet towels. Thoroughly wet their coat with water cooler than their body and initially cool them quickly.
Evidence based measures, from Dr Marlin, discussed here.
This is an EMERGENCY! Act accordingly.
What’s most important, is that cooling measures (or, stopping the heating measures) are in place as quickly as possible and those measures stop body temperature increases and drop body temperature fast. Drobatz & Macintire 1996, found that, without cooling measures before getting to the vet, almost half of the dogs with HRI died. And this risk more than halved where cooling measures were implemented earlier.
Cooling measures should be applied even as you travel to the vet. Remember that the back of the car is usually a good deal hotter than the front seats so ventilate well.
Brachycephalic dogs are more likely to die from HRI but are not more likely to develop severe disease. Hall et al, 2022, suggests that these dogs are at greater risk of respiratory failure earlier. That’s why treating even early signs FAST is so important, especially in dogs with underlying conditions such as respiratory issues.
HRI can lead to longer term complications; even if cooling measures are successful at the scene and the dog appears recovered – they must see a vet and quick.
Review and Share Evidence Based Information:
- Dr David Marlin is an excellent source and active, with lots of resources, on socials.
- Canine Heat Injury Prevention & Field Treatment Facebook page is an excellent source of evidence based and practical information.
- Heatstroke.dog
- Veterinary Voices UK
- The Veterinary Tactical Group are conducting ongoing data collection and research in this area.
Get them wet. Get them to the vet.
This is truly life-saving information. And evidence-based:
You can wet the dog, right down to their skin, with cold water and you won’t cause “shock”. Keep wetting them.
Don’t cover them up. Don’t think that just wetting limited body areas will be sufficient. It won’t.
Indeed cold water immersion can be more effective. But is not safe for unconscious dogs, weak dogs, or dogs that may be difficult to manage for the first-aider. That’s why I promote getting them wet, down to the skin. And getting them to the vet, even if they seem recovered and well.

















































