Dog heatstroke prevention is about more than avoiding hot cars. Dogs can overheat during exercise, at home, in the garden or anywhere they are exposed to more heat than their bodies can safely lose.
One of the most important things to understand is that there is no single outdoor temperature that is safe for every dog. Exercise, humidity, direct sun, ventilation, the length of exposure and the individual dog all affect the risk.
In fact, UK veterinary research has found that exercise is a particularly important cause of heat-related illness in dogs. That means preventing heatstroke starts with knowing when to change your dog’s normal routine — and when the safest decision is to stop an activity altogether.
Heatstroke prevention at a glance
- Exercise your dog during cooler conditions and reduce the length and intensity of activity when necessary.
- Be prepared to skip a walk if conditions are unsuitable.
- Make sure your dog has access to fresh drinking water.
- Provide shade and good ventilation.
- Never leave your dog in a warm car or another enclosed space that can overheat.
- Take extra precautions if your dog is particularly vulnerable to heat.
- Watch your dog rather than relying only on the temperature shown by a weather app.
- Stop exercise and act promptly if your dog starts showing signs of overheating.
If your dog is already showing possible signs of heatstroke, such as excessive panting, weakness, confusion, vomiting or collapse, prevention is no longer the priority. Move them away from the heat, start cooling them and contact a vet urgently. Our complete guide to dog heatstroke explains the condition and what to do next.
What Causes Heatstroke in Dogs?
Heatstroke develops when a dog’s body becomes dangerously hot and can no longer lose heat quickly enough to keep its temperature under control.
Dogs rely heavily on panting to lose excess heat. This cooling system can become overwhelmed when a dog produces a lot of heat through exercise, is exposed to a hot environment, cannot escape somewhere warm or has physical characteristics that make cooling less effective.
The result is not simply that the dog feels uncomfortably warm. Severe heat-related illness can cause organ damage and can be fatal, so prevention matters.
Exercise is a bigger heatstroke risk than many owners realise
Hot cars receive a lot of attention for good reason, but exercise is a major cause of canine heat-related illness.
Exercise is the leading trigger in UK research
A UK VetCompass study examining 905 heat-related illness events found that 74.2% were triggered by exertion, compared with 12.9% caused by environmental heat and 5.2% associated with confinement in a hot vehicle.
This changes how you should think about prevention.
A dog does not need to be locked in a baking-hot car to develop heatstroke. Running, energetic play, a long walk or strenuous exercise can generate a substantial amount of body heat, particularly when environmental conditions make it harder for the dog to cool down.
Some dogs may also remain enthusiastic about exercise even when they are becoming too hot. It is therefore up to the owner to make the safer decision rather than waiting for the dog to decide that it has had enough.
Heatstroke can also develop without strenuous exercise
Dogs can also overheat when they are confined somewhere warm or cannot move to a cooler environment.
Examples include:
- cars and other vehicles;
- conservatories and sunrooms;
- poorly ventilated rooms;
- caravans;
- gardens without adequate shade;
- direct sunlight for prolonged periods.
Dogs can therefore develop heat-related illness indoors as well as outside. Can Dogs Get Heatstroke Indoors? looks more closely at how indoor overheating happens and the situations that deserve particular care.
How to Prevent Heatstroke During Walks and Exercise
Changing how you exercise your dog is one of the most important ways to reduce the risk of heatstroke.
Choose cooler conditions
On warm days, early morning or later evening will often be cooler than the middle of the day.
But don’t treat the time of day as a guarantee of safety. During very hot weather, conditions may remain unsuitable well into the evening, and high humidity can make it harder for a dog to lose heat through panting.
Check the actual conditions before setting out and consider the dog you are taking with you.
If you are unsure whether conditions are suitable, our guide to deciding whether it is too hot to walk your dog gives you a more detailed decision process.
Reduce the intensity as well as the length of exercise
A shorter walk helps, but intensity matters too.
Running, chasing a ball and energetic play generate considerably more body heat than a slow walk. On warmer days, consider replacing vigorous exercise with a shorter, gentler outing with plenty of time for sniffing.
You can also use indoor training, scent games or other low-intensity enrichment when outdoor exercise is not sensible.
Missing or shortening a walk because of dangerous heat is preferable to trying to maintain a normal exercise routine regardless of the conditions.
Take water and allow proper breaks
Take fresh drinking water with you, particularly on longer walks and warm days, and give your dog regular opportunities to drink.
Rest breaks should genuinely allow your dog to cool down. Find shade where possible and avoid immediately starting another burst of energetic activity.
Water is an important part of heat safety, but access to water does not make strenuous exercise in dangerous conditions safe.
Watch the dog as well as the weather
Two dogs on exactly the same walk can respond differently.
Pay attention to changes in your dog’s breathing, pace, behaviour and willingness to continue. If your dog is panting much more heavily than expected, repeatedly slowing down, seeking shade or otherwise appearing uncomfortable, stop the activity and move somewhere cooler.
Don’t wait for a predetermined temperature or distance to tell you that the dog has had enough.
Watch your dog, not just the thermometer
There is no single outdoor temperature that is safe for every dog. Exercise, humidity, direct sun, duration and your dog’s individual vulnerability all affect the risk. If your dog is struggling with the heat, stop the activity and move somewhere cooler.
Keep Your Dog Cool at Home and in the Garden
Heatstroke prevention matters at home too, particularly during sustained periods of hot weather.
Your dog should have access to:
- fresh drinking water;
- a cool resting area;
- shade away from direct sunlight;
- sufficient ventilation;
- the ability to move away from warmer parts of the home or garden.
Rooms exposed to strong sunlight can become considerably warmer than other parts of a house. Conservatories are an obvious example, but bedrooms, kitchens and other rooms can also become uncomfortable when sunlight enters through large windows.
Closing curtains or blinds on sun-facing windows may help reduce solar heating. Opening suitable windows and doors can improve air movement when doing so is safe and the outside air is cooler.
Fans can also help create air movement, although they should be used as part of a wider cooling strategy rather than as proof that a hot room is safe. See Are Fans Safe for Dogs? for practical guidance on using them appropriately.
In the garden, make sure shade remains available as the sun moves. A spot that is shaded in the morning may be in full sun later in the day.
Most importantly, give your dog the option of moving somewhere cooler rather than expecting them to remain outside simply because water and shade have been provided.
Never Leave Your Dog in a Hot Car or Other Enclosed Space
Never leave a dog unattended in a car on a warm or hot day.
Opening a window slightly or parking in the shade does not remove the danger. The temperature inside a vehicle can rise rapidly, leaving a dog unable to escape the heat.
Plan journeys so that your dog does not need to be left in the vehicle while you stop somewhere they cannot accompany you.
The same principle applies to other enclosed spaces that can become dangerously warm, including caravans and conservatories.
If you are planning to travel during warm weather, think about heat exposure before leaving home: the temperature inside the vehicle, ventilation or air conditioning, drinking water, journey length and where you can safely stop all matter.
Which Dogs Need Extra Heatstroke Precautions?
Any dog can develop heatstroke, but some dogs have less margin for error.
Flat-faced dogs
Brachycephalic — or flat-faced — dogs such as French Bulldogs, English Bulldogs and Pugs are particularly vulnerable.
Dogs lose a substantial amount of heat through panting. Shortened airways and breathing problems can make this less effective in brachycephalic dogs.
UK veterinary research has consistently identified brachycephalic conformation as an important heat-related illness risk factor.
For these dogs, it is sensible to be particularly conservative about exercising in warm conditions.
Overweight dogs
Excess bodyweight is another recognised risk factor.
Keeping your dog at a healthy weight has benefits far beyond hot-weather safety, but it can also improve their ability to cope with warmer conditions.
If you are unsure what a healthy weight looks like for your dog, ask your vet or veterinary nurse for advice rather than relying solely on a number on the scales.
Older dogs and dogs with health problems
Older dogs and dogs with certain medical conditions may be less able to cope with heat or strenuous activity.
Respiratory and cardiovascular problems are particularly relevant because efficient breathing and circulation are important parts of temperature regulation.
If your dog has a medical condition that could affect their ability to exercise or tolerate heat, ask your vet about appropriate activity during warmer weather.
Young, large, heavily coated and poorly acclimatised dogs
Age, body size, coat and acclimatisation can also influence how well an individual dog copes with heat.
These factors should not be used to create a rigid hierarchy of supposedly “safe” and “unsafe” dogs. Instead, think of them as reasons to increase the margin of safety.
For a closer look at individual susceptibility, Dog Breeds Most at Risk of Heatstroke explores how breed, body shape and other characteristics can affect heat-related illness risk.
Plan Ahead Before Walks and Days Out
A simple way to prevent heatstroke is to assess five things before committing to an activity:
| Check | Ask yourself |
|---|---|
| Weather | How warm and humid is it? Is there strong direct sun? Are conditions expected to become hotter? |
| Dog | Is my dog flat-faced, overweight, elderly, unwell or otherwise particularly vulnerable? |
| Activity | How strenuous will this be, and how long will it last? |
| Environment | Will there be reliable shade, drinking water and somewhere genuinely cool to rest? |
| Exit plan | Can I stop immediately and get my dog somewhere cooler if conditions change or the dog starts struggling? |
The answer does not have to be “don’t go”.
You might instead shorten the walk, change the route, leave earlier, replace running with a gentle stroll or move an activity indoors.
But if you cannot make the activity suitably safe, postponing it is a perfectly reasonable decision.
Signs Your Dog Is Getting Too Hot
Prevention includes noticing when your dog is no longer coping comfortably with the conditions.
Possible warning signs include:
- unusually heavy or persistent panting;
- excessive drooling;
- slowing down or stopping during exercise;
- difficulty breathing;
- restlessness or distress;
- weakness or poor coordination;
- confusion;
- vomiting or diarrhoea;
- collapse.
These signs are not a checklist that every dog will follow in the same order, and some can occur for reasons other than heatstroke.
What matters is recognising that a dog showing concerning signs after exercise or heat exposure needs prompt attention.
Our guide to the early warning signs of dog heatstroke explains what to look for and which signs indicate a more serious emergency.
What to Do If You Think Your Dog Is Developing Heatstroke
Heatstroke is an emergency. If you think your dog is overheating:
- Stop the activity and move the dog away from the heat.
- Start cooling them immediately.
- Contact a vet as soon as possible.
- Continue cooling while arranging veterinary care and during transport where practical and safe.
Current UK veterinary guidance supports a “cool first, transport second” approach rather than delaying cooling until the dog reaches the veterinary practice.
Do not cover a hot dog with a wet towel. A wet towel placed over the body can trap heat rather than allowing it to escape.
Cooling is first aid, not a substitute for veterinary assessment. A dog can appear to improve while still being at risk of complications following serious heat-related illness.
For a step-by-step emergency sequence, see Dog Heatstroke First Aid: What to Do in an Emergency.
Common Heatstroke Prevention Mistakes
Thinking heatstroke only happens in cars
Hot cars are extremely dangerous, but exercise causes many heat-related illness cases in dogs.
Prevention therefore needs to include walks, running, play and other physical activity.
Looking for one “safe” outdoor temperature
A single air-temperature number cannot account for humidity, direct sunlight, exercise intensity, duration, acclimatisation or differences between individual dogs.
Use temperature as one part of the decision, not the whole decision.
Assuming your dog will stop when they become too hot
Excited dogs may continue running or playing despite accumulating heat.
You may need to end the activity before your dog chooses to stop.
Thinking shade and water eliminate the risk
Both are important, but neither makes otherwise dangerous conditions safe.
A dog exercising hard can still overheat despite drinking water, and a dog in the shade can still struggle when the surrounding air is very warm or humid.
Relying on a cooling product to make an unsafe activity safe
Cooling mats, fans, paddling pools and other cooling aids can have useful roles, but they should support sensible heat management rather than replace it.
If the underlying conditions are unsuitable for the dog or the planned activity, changing the activity is the safer response.
Waiting for severe symptoms
Collapse, seizures and severe breathing difficulty are not the point at which you should first respond.
Stop exercise when a dog begins showing signs that they are struggling with the heat. If heatstroke is suspected, start cooling and seek veterinary help promptly.
Dog Heatstroke Prevention Checklist
Before a walk or activity
- Check the weather and expected conditions.
- Consider your dog’s individual heat risk.
- Choose a cooler time and route where possible.
- Reduce the length or intensity when appropriate.
- Take drinking water.
- Know where shade or a cooler environment will be available.
- Be willing to change or cancel the activity.
During exercise
- Watch your dog’s breathing and behaviour.
- Keep the pace appropriate to the conditions.
- Avoid prolonged strenuous running or play in warm weather.
- Provide water and proper rest breaks.
- Use shade where possible.
- Stop if your dog begins struggling with the heat.
At home
- Keep fresh water available.
- Provide cool resting areas.
- Prevent prolonged exposure to direct sunlight.
- Maintain safe ventilation.
- Monitor rooms that heat rapidly.
- Make sure your dog can move somewhere cooler.
When travelling
- Never leave your dog unattended in a warm vehicle.
- Keep the vehicle comfortably ventilated or air-conditioned.
- Provide water.
- Plan stops before setting out.
- Avoid unnecessary travel during dangerous heat.
If your dog starts showing signs of heatstroke
Stop → move them away from the heat → start cooling → contact a vet.
Frequently Asked Questions
Can a dog get heatstroke when it isn’t extremely hot?
Yes. Heat-related illness is not caused by air temperature alone. Exercise generates body heat, while humidity, direct sunlight, ventilation, duration of exposure and the dog’s individual characteristics affect how efficiently that heat can be lost.
This is one reason strenuous exercise can cause heatstroke even when the weather does not seem exceptionally hot to a person.
Can a dog get heatstroke indoors?
Yes. A dog can overheat in a warm, poorly ventilated indoor environment, particularly if they cannot move somewhere cooler or have individual risk factors that make temperature regulation more difficult.
Can Dogs Get Heatstroke Indoors? explains the indoor risks and practical precautions in more detail.
Can a dog get heatstroke in the shade?
Yes. Shade helps by reducing direct solar heating, but it does not control the surrounding air temperature, humidity or heat generated by exercise.
Shade is therefore an important precaution, not a guarantee that a dog cannot overheat.
The Bottom Line
Preventing heatstroke means looking at the whole situation rather than searching for one supposedly safe temperature.
Think about your dog, the weather, the activity and the environment together. Adjust exercise before your dog struggles, provide water, shade and ventilation, avoid dangerous enclosed spaces and take extra precautions with dogs that are more vulnerable to heat.
And if your dog starts showing signs that heatstroke may already be developing, stop thinking in terms of prevention: start cooling them and contact a vet promptly.