Summer Heat and Your Dog: How to Keep Walks Safe

In brief

Four things keep summer with your dog safe. First: the most common situation in which dogs overheat is not the hot car but the perfectly ordinary walk – in a British analysis of more than 900,000 dogs, 74.2 percent of heat-related cases with a known trigger were due to exertion, and two thirds of those simply followed a walk. Second: there is no temperature threshold above which it becomes dangerous – bulldogs can overheat in a room at just 21 °C. Third: the ground is often a bigger problem than the air, and it stays that way well into the evening. And fourth: if it does happen, use cold water – not lukewarm.

Summer walks aren’t the problem, as long as you adapt them. This guide is about how to choose the time, route, and pace so that you both get something out of it – and how to tell when it’s enough.

👉 The basics of preventive care and health checks in dogs

1. Why heat is a different problem for dogs

Dogs shed heat mainly by panting. They do have sweat glands in their paw pads – these can contribute to thermoregulation, but are of only minor importance compared with panting. So dogs don’t sweat in the real sense; they lose heat through evaporation from the airways.

That also explains why a fixed temperature threshold doesn’t work. You often read that above a certain value, panting is no longer enough. It isn’t that simple: English bulldogs have been observed to overheat just from standing in a room at 21 °C. What matters is not the number on the thermometer but the interplay of temperature, humidity, exertion, fitness, build, and acclimatization.

In practice, this means: watch your dog, not the thermometer.

2. Who should be especially careful

The risk profiles differ depending on how the overheating comes about (Hall et al., 2020). This is relevant because it corrects a widespread assumption.

With exertion – on walks, during play, during sport:

• Young dogs. Dogs over eight years had lower odds of an exertion-related case than dogs under two.
• Larger and heavier dogs. All weight classes from 10 kg up were higher than dogs under 10 kg.
• Active family and working breeds. Labrador Retrievers had 2.1 times the odds compared with mixed breeds, with similar results for Boxers, Golden Retrievers, and Border Collies.

This is the surprising point: in the most common form, it is disproportionately often the young, strong, athletic dog who is affected – not the senior.

With environmental heat alone:

• Short-nosed dogs (brachycephalic breeds). 2.36 times the odds compared with dogs with a medium-length muzzle; the obvious explanation is their limited ability to shed heat by panting. Pugs, bulldogs, Boxers, Shih Tzus.
• Old dogs. From twelve years on, 3.15 times the odds compared with dogs under two.
• Dogs with pre-existing conditions, especially of the heart, circulation, or airways.
• Overweight dogs. More mass, poorer heat loss.

On dark coats: that a dark coat heats up more in the sun is physically plausible, but it doesn’t appear as an independent factor in the large risk-factor analyses. Treat it as an additional consideration, not as a main criterion.

3. The walk is the main danger – not the car

This is the most important shift compared with the usual summer advice, and it concerns exactly the subject of this guide.

In the largest study on this to date, 905,543 dogs in British primary veterinary care were analyzed. Of the heat-related events with a known trigger, 74.2 percent were due to exertion, 12.9 percent to environmental heat, and 5.2 percent to being shut in a vehicle (Hall et al., 2020).

And within the exertion-related cases where the activity was recorded: 67.5 percent occurred after a walk. Only 17.6 percent occurred after intense activities such as running or cycling, and 13.8 percent after play.

So the typical case is not the dog forgotten in the car, and not the overexcited sports dog. It is the usual walk in weather that’s too warm – taken by someone who had no intention of doing anything wrong.

That’s why the most important sentence in this guide is unspectacular: on hot days, even the normal walk is a decision, not a given. Shortening it, moving it to another time, or skipping it and replacing it with calm activities somewhere cool are all three legitimate answers.

4. The right time

The cool morning hours and late evening are the obvious windows. The popular time-of-day rules – before nine, after eight, avoid the midday hours – are a useful guide, but they aren’t measurements. What matters are the actual conditions: the position of the sun, humidity, wind, shade along the route, the ground surface.

One point that often gets lost: asphalt cools down very slowly. It stores the day’s heat and can still be considerably warmer than the air long after sunset. So the evening walk isn’t automatically the safe one – check the ground then, too.

And about the popular tip of simply driving to the lake at midday: that can work if you can get straight into the water and the way there is short and shady. The catch lies in getting there and in the walk from the parking lot. A dog who walks twenty minutes across an open meadow to the water at 30 °C has already done the exertion before the cooling off begins.

5. Ground and route

It isn’t the air temperature alone that matters, but the surface underfoot.

Dark asphalt in the sun can reach around 50 °C at an air temperature of about 25 °C, and goes considerably higher on hot days. Burns to the paw pads can occur on correspondingly hot surfaces.

The ground test: place the back of your hand on the surface for about seven seconds. If you can’t stand it, it’s too hot for your dog’s paws. This isn’t a measuring method, but it’s a good rule of thumb.

Important here: the paws are not an indicator of the overall heat load. A cool forest floor doesn’t protect against the walk being too much overall. Conversely, the ground may long since be too hot while the air still feels pleasant.

Well suited: dense forests with cool ground, field and meadow paths away from paved roads, shady paths along the water. Shade lowers the surface temperature considerably.

If asphalt can’t be avoided: keep the route short, choose the shady side of the street, use green spaces for breaks.

6. Out and about

Slow down. Let your dog sniff and dawdle. A dog who is using their nose is getting a workout without overexerting themselves.

Split up exercise. Several short walks spread over the day are better in the heat than one long route.

Bring water. A collapsible bowl or a dog water bottle, every time you go out.

Breaks in the shade or by the water. A short stop in a stream brings noticeable relief.

Train an interrupter cue and recall. This is where training can concretely prevent emergencies. Many dogs don’t regulate themselves in the heat – a ball-crazy dog or one driven to hunt often won’t stop on their own just because they’re too warm, but they will if you can call them back. A reliable recall and a properly built interrupter cue are safety equipment in summer.

About damp cloths. A dampened cloth in your backpack sounds practical, but as a cooling method it’s not very effective – laid on the dog, it tends to insulate rather than cool. As a wet surface to lie on, it makes sense; as a cover on the dog, it doesn’t.

7. At home: the other half of summer

The chapters above deal with the walk – the most common source of danger. The second largest is environmental heat, and it mainly affects the groups from chapter 2: short-nosed dogs, old dogs, dogs with pre-existing conditions. For them, the home matters more than the walk.

7.1 Keeping your home cool

Air out at night and early in the morning, keep windows shut during the day – and do it consistently. A window left open from ten in the morning heats the room up instead of cooling it.

External shading beats interior blinds. Whatever is kept out doesn’t have to be removed from inside. Where that’s not possible, light-colored curtains or reflective film on the sunny side help.

A fan doesn’t cool the room, it improves evaporation. For a panting dog, that’s exactly what’s useful – but only if they can also move out of the airflow. Don’t point it directly at their bed.

The coolest spot is rarely the one you picked. Many dogs lie down in hallways, bathrooms, or on tiles. Clear those spots instead of insisting that the dog bed be used.

7.2 The balcony, the car, the yard

On the balcony, the shade moves. A dog who was lying in the shade at noon is lying in the sun at four – and can’t escape if the door is closed.

In the yard, you need shade that lasts all day, and water that isn’t standing in the sun. A bowl on the patio is warm by midday.

In the car, the simplest rule in this guide applies: not at all. Not briefly, not in the shade, not with the window cracked. A parked car can heat up within minutes to levels that panting can no longer cope with.

7.3 And feeding

Many dogs eat less in the heat – that’s normal and no cause for concern as long as they drink and are lively. It makes sense to move the main meal to the cool hours, not to leave food sitting out, and to make sure fresh water is available in several places.

8. Cooling aids: what works and what doesn’t

The market is full of them in summer, and their effectiveness varies considerably. The common yardstick: dogs cool down through evaporation. Whatever supports evaporation helps – whatever hinders it doesn’t.

A wet towel to lie on: useful. Laid over the dog, on the other hand, it isn’t – a towel lying snugly on the dog quickly warms up and then hinders heat loss.

Cooling vests work through evaporation and therefore only as long as they’re damp and air can flow past them. In muggy air or in blazing sun, the effect wears off quickly. Re-wet them regularly, or the vest becomes an additional layer.

Gel-filled cooling mats absorb heat until they’re saturated – after that they no longer work and feel warm to the dog. They need recovery time in the shade. And some dogs simply avoid them; that’s not stubbornness but feedback.

A shallow paddling pool is an effective and inexpensive measure – provided it’s in the shade and the water is changed. Water that has warmed up doesn’t cool.

Wetting the coat works if the water gets through to the skin and there is air movement as well. Dense fur that is only dampened on the surface, on the other hand, can act like a damp layer that tends to hinder heat loss – especially in dogs with a lot of undercoat.

Ice cubes and frozen treats are a good activity and a nice way to cool down from the inside. As a measure against real overheating, they don’t work – the amount is too small for that.

And clipping: for dogs with a dense undercoat, brushing out is as a rule more sensible than clipping, because the topcoat also protects against sun exposure. Whether a clip is right in an individual case depends on the coat type and should be discussed with someone who knows your dog’s coat.

9. How to tell when it’s getting too much

Some dogs show clearly when they’re overheating. Others keep going despite exhaustion – that’s the more dangerous type.

Early signs: panting more intensely than usual without recovering during breaks, restlessness, seeking shade or cool ground, slowing down, dawdling that doesn’t look like sniffing.

Alarm signs: unsteady gait, staggering, vomiting or sudden diarrhea, very red, pale, or bluish gums, thick saliva, muscle tremors, lethargy, collapse.

On body temperature: the normal range is roughly between 37.5 and 39 °C. Values above that are a warning sign that always has to be assessed in the overall picture – a dog who has just been running will be temporarily higher without being ill. Temperatures from about 41 °C upward are considered critical. But a single number never replaces looking at the dog’s condition.

10. If it does happen

The short version – you’ll find the full version in the guide on heatstroke in dogs:

Cool first, then drive. That is what the veterinary guidelines on first aid say. Don’t put your dog in the car and set off – start cooling on the spot.

Cold water, whole body. The widespread warning that you may only use lukewarm water because otherwise the blood vessels constrict is considered refuted in the specialist literature. Use cold tap water or whatever water is available nearby, and pour it over the whole body – not just the paws and belly. Keep the head clear. Stream, garden hose, tub, bucket.

Create air movement. Water plus airflow cools considerably better than water alone.

Stop the exertion immediately, get into shade or a cool room.

Offer small amounts of water, never force it. A dog with impaired consciousness gets nothing to drink.

Call the vet and go there – even if things improve. Organ damage can show up with a delay.

11. Conclusion

High temperatures don’t mean your dog has to go without walks. They mean the walk itself becomes a decision.

The three things that count:

Watch your dog, not the thermometer. There is no safe number of degrees.

Check the ground – in the evening, too. Asphalt holds the heat for a long time.

Be ready to skip the walk. On some days, a sniffing game in a cool hallway is a better activity than the usual route.

Summer offers plenty of chances to experience things together – early in the morning, in the shady forest, by the water. It’s not about doing less, but about doing things differently.

Key takeaways about summer with your dog

The walk is the main danger, not the car. In an analysis of 905,543 dogs, 74.2 percent of heat-related events with a known trigger were due to exertion and 5.2 percent to the vehicle – and two thirds of the exertion cases followed a walk (Hall et al., 2020).

There is no temperature threshold. English bulldogs can overheat just from standing in a room at 21 °C. Watch your dog, not the thermometer.

In exertion-related cases, it is disproportionately the young, strong dog who is affected – not the senior. Seniors and short-nosed dogs rank highest for environmental heat.

The ground is often a bigger problem than the air. Dark asphalt can reach around 50 °C at an air temperature of 25 °C – and it cools down slowly, so the evening walk isn’t automatically safe.

The paws are not a measure of the overall load. A cool forest floor doesn’t protect against the walk being too much overall.

Cooling aids work through evaporation – or not at all. Cooling vests have to stay damp, gel mats become saturated, and a wet cloth laid on the dog tends to hinder heat loss rather than support it.

If it does happen: cold water, not lukewarm. The old warning against it is now considered outdated.

References

• Hall, E. J., Carter, A. J., & O'Neill, D. G. (2020). Dogs don't die just in hot cars – Exertional heat-related illness (heatstroke) is a greater threat to UK dogs. Animals, 10(8), Artikel 1324. https://doi.org/10.3390/ani10081324

• Hall, E. J., Carter, A. J., Bradbury, J., Beard, S., Gilbert, S., Barfield, D., & O'Neill, D. G. (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(7), Artikel 465. https://doi.org/10.3390/vetsci10070465

• Lilja-Maula, L., Lappalainen, A. K., Hyytiäinen, H. K., Kuusela, E., Kaimio, M., Schildt, K., Mölsä, S., Morelius, M., & Rajamäki, M. M. (2017). Comparison of submaximal exercise test results and severity of brachycephalic obstructive airway syndrome in English bulldogs. The Veterinary Journal, 219, 22–26. https://doi.org/10.1016/j.tvjl.2016.11.019

On the asphalt figure: The order of magnitude “around 50 °C surface temperature on dark asphalt in the sun at an air temperature of about 25 °C” comes from educational material published by animal welfare and burn care organizations and is consistent with several independent compilations. We have not checked a single peer-reviewed primary source with exactly this pair of values; the actual surface temperature depends heavily on solar radiation, surface color, wind, and time of day.

Note: This guide does not replace a veterinary examination or treatment. If you suspect overheating, start cooling immediately and contact your veterinary clinic or an emergency veterinary service right away.

Frequently asked questions about summer with your dog

How to protect your dog from overheating in summer – with smart tips on timing, route, and behavior