As dogs aren’t as good as humans at regulating their body temperature, warmer weather can mean that heatstroke is a real risk.
Heatstroke is a serious condition that needs urgent vet treatment, so it’s important owners understand why it happens, the warning signs to watch out for, and how to treat it. Below, we’ll go through everything you need to know to keep your dog safe.
Heatstroke – also referred to as hyperthermia or heat exhaustion – happens when dogs get so hot they can no longer lower their body temperature by panting or sweating through their paw pads.
A dog’s normal body temperature should be around 38-39°C (100.4-102.2°F), but when this rises above 40°C (104°F), dog heatstroke can occur.
When dogs overheat and develop heatstroke, it can be life-threatening.
Dogs rely on panting to help them regulate their body temperature, but panting becomes less effective as they get hotter.
When a dog’s temperature rises too high, normal body functions are affected. Extreme heat and dog heatstroke can damage your pet’s organs, causing issues such as brain swelling, kidney failure, seizures, internal bleeding and respiratory problems.
While any dog can get heatstroke, some are more at risk than others. This includes:
Knowing the warning signs can help you spot when your dog might be overheating. Here are the early signs to watch out for, as well as the severe symptoms that require emergency attention.
Initial dog heatstroke signs can be easy to miss, particularly if your dog has been exercising or they’re excited. But be wary of:
If you’re unsure about initial signs – and have dog insurance with Petplan – use our Pet Expert Chat feature to ask any non-urgent health questions to a vet expert. Just log into your My Petplan account to get started.
If heatstroke progresses, symptoms can become more severe and require veterinary attention. If you notice any of the below, it’s important to contact your vet urgently.
Remember, you know your dog best. If you’re at all worried about your dog overheating – even if their symptoms don’t exactly match the above – it’s always best to consult your vet.
Puppies can develop heatstroke in the same way as adult dogs, but as they’re more vulnerable, it’s especially important to keep an eye out for the symptoms outlined above.
Heatstroke in puppies can occur because they’re not as good as adult dogs at regulating their temperature. They are also typically more energetic and may not realise when to cool down or rest.
Heatstroke symptoms in puppies are similar to those in adult dogs, so keep an eye out for heavy panting, drooling, lethargy and bright red gums. Puppies might become noticeably less active, too.
Just like with adult dogs, if you’re concerned, it’s best to contact your vet. In the meantime, move them somewhere cool and encourage them to rest.
Heatstroke and sunstroke are often used interchangeably to describe heat-related illness – but they’re not quite the same.
In simple terms, sunstroke in dogs is overheating caused by direct exposure to sunlight and UV rays. Heatstroke, meanwhile, is when a dog’s body temperature rises to a level they’re unable to regulate on their own and cool down.
Both heatstroke and sunstroke in dogs have similar symptoms, such as panting, confusion, vomiting and collapse.
However, dogs don’t need to be in direct sunlight to develop heatstroke. They might develop heatstroke after exercising in warm weather or being left in a hot environment, for example.
If you have any concerns – even if you’re unsure whether they’re showing dog sunstroke symptoms or signs of heatstroke – it’s best to contact your vet.
Research shows the top three causes of heatstroke for dogs in the UK are exercising in hot weather, being left in a hot vehicle, and being unable to cope with heat due to age or breed.
So, helping your dog stay as cool and comfortable as possible will minimise the risk of them developing dog heatstroke.
Going for walks in the early morning or late evening when it’s cooler will help reduce the risk of heat or sunstroke in dogs. If it's too hot, replace your usual walks with safer hot-weather activities instead.
Before heading out, check our Furcast tool. Simply enter your dog's type and location to see whether the temperature is safe for walkies or not.
Always provide plenty of shade and water, whether you’re at home or visiting a dog-friendly place for some fun.
The risks of heatstroke increase when a dog doesn’t have access to shade or water – but if their body temperature has risen enough, they can develop heatstroke even in the shade or with ample water.
Never leave your dog in a vehicle, even for a short time. Be mindful of hot surfaces, too, such as the pavement – as well as the heatstroke risk, dogs can burn their sensitive paws.
Before heading out, try placing your hand on the pavement for a few seconds. If it feels too hot, it’s likely to be too hot for your dog’s paws.
Keeping your dog hydrated is vital, but on top of cool, fresh water, you could offer them some tasty frozen summer snacks, add ice cubes to their water bowl, buy a cooling gel mat, or give them a damp towel to lie on.
Dog heatstroke is a medical emergency, so always contact your vet for urgent treatment. Follow their advice, which may include taking steps to reduce your dog’s temperature at home before travelling to the clinic.
It’s no longer recommended to cool your dog down by placing wet towels over their body, as this can end up trapping heat.
It’s a good idea to contact your vet regardless, but if you notice any of the severe symptoms listed, it’s important to reach out urgently.
When you get to the vet, your dog may need additional treatment, including fluids, oxygen and medication.
If left untreated, heatstroke can cause organ failure and even death – so the quicker you recognise the signs and seek vet help, the more likely your dog will make a full recovery.
Heatstroke in dogs is a serious condition, but being aware of how to prevent it – as well as the initial warning signs and symptoms – can help you to act quickly and reduce the risks.
Many dogs are comfortable in temperatures up to 20°C, but different dogs will have different thresholds.
Temperatures above 25°C are more likely to increase the risk of heatstroke, but the conditions that trigger it vary between dogs.
The duration of heatstroke can vary, depending on how quickly a dog receives treatment, how severe their symptoms are, and additional factors such as age and overall health. Some dogs can recover relatively quickly, while others might develop complications that mean it takes a little longer to recover.
Yes, dogs can develop heatstroke indoors if it’s warm and there’s insufficient shade, ventilation and/or access to cool areas. No matter the temperature outside, it’s always important to ensure your dog has access to fresh water and cool places to rest.
Last updated: 7 September 2026
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