As temperatures rise across Spain and the rest of Europe, keeping your dog cool in summer becomes one of the most important responsibilities of pet ownership. Dogs are far more vulnerable to heat than humans, and the consequences of overheating can escalate within minutes. Whether you are heading out for a walk, spending the day at the beach, or simply managing the heat at home, this guide covers everything you need to know to keep your dog safe, comfortable, and healthy throughout the warmer months.
Why Dogs Struggle with Heat
Unlike humans, dogs do not sweat through their skin. They regulate body temperature almost entirely through panting, which exchanges hot air from the lungs with cooler external air. At rest, a healthy dog breathes around 15 to 30 times per minute. When panting to cool down, that rate can exceed 300 to 400 breaths per minute according to veterinary physiology guidelines. It is an energy-intensive process, and in high humidity or extreme heat, it simply cannot keep pace with rising body temperature.
According to veterinary emergency medicine guidelines, a dog's normal body temperature sits between 38°C and 39.2°C. Heat exhaustion begins around 40°C, and heat stroke, which can cause organ failure and brain damage, sets in at 41°C or above. At 43°C, the condition is almost always fatal without immediate veterinary intervention.
Brachycephalic breeds (Bulldogs, Pugs, French Bulldogs) are at significantly higher risk because their restricted airways make panting less effective. Most veterinary experts also consider older dogs, overweight dogs, and those with thick double coats to be higher-risk groups during hot weather.
How Hot Is Too Hot for a Dog Walk?
Veterinary guidelines broadly suggest that when air temperature exceeds 25°C, the risk of heat-related illness during exercise increases meaningfully for most dogs. Above 32°C, outdoor exercise should be kept very short and limited to shaded areas. Humidity compounds the risk significantly, as moist air reduces the efficiency of panting.
Ground temperature is equally important. Research published in veterinary and emergency medicine literature has shown that on a 25°C day, asphalt can reach 52°C. At 30°C ambient temperature, that surface can exceed 60°C, hot enough to cause burns to paw pads within 60 seconds. The seven-second test is a reliable field check: press the back of your hand firmly to the pavement. If you cannot hold it there for seven seconds, it is too hot for your dog to walk on.
Signs of Overheating in Dogs
Recognising the early warning signs of heat exhaustion can prevent a serious situation from becoming fatal. Watch for:
- Excessive, heavy panting that does not slow with rest
- Drooling more than usual, sometimes with thick or foamy saliva
- Bright red or pale gums (normal gum colour is bubble-gum pink)
- Lethargy, weakness, or reluctance to move
- Vomiting or diarrhoea
- Loss of coordination or stumbling
- Glazed eyes or visible confusion
According to VCA Animal Hospitals, even on a 20°C day, the interior of a parked car can reach 40°C within 30 minutes and 47°C within an hour. Cracking a window makes almost no measurable difference to interior temperature.
Practical Ways to Keep Your Dog Cool in Summer
1. Adjust Walk Times
Shifting walks to before 9am or after 7pm during peak summer months is the single most effective behavioural change you can make. Ground temperatures drop significantly after sunset and remain lower in the early morning before surfaces have had time to absorb the day's heat. In Spain, where July and August regularly see temperatures above 35°C in inland cities, most veterinary experts consider this adjustment essential rather than optional for many breeds.
2. Use a Cooling Vest
Cooling vests work through evaporative cooling: the vest is dampened with water, and as that water evaporates, it draws heat away from the dog's body. Veterinary sports medicine specialists suggest that evaporative cooling can reduce a dog's skin surface temperature by 3°C to 5°C during outdoor activity, meaningfully reducing the thermal load on the body. A well-fitted breathable dog cooling vest is particularly useful for active dogs, working breeds, and any dog that needs to be outdoors during warmer parts of the day. Re-dampen every 20 to 30 minutes in direct sun for best results.
3. Keep Fresh Water Available at All Times
Most veterinary nutritional guidelines suggest dogs need approximately 50 to 60ml of water per kilogram of body weight per day under normal conditions. In hot weather or during exercise, that requirement can double. A 20kg dog may need over 2 litres of water on a hot summer day. At home, place multiple water bowls in shaded spots and refresh them every few hours. When out and about, always carry water for your dog. A portable travel water bottle with an integrated bowl makes it easy to offer your dog a drink wherever you are, without needing to find a tap or carry a separate container.
4. Create a Cool Environment at Home
Keep curtains or blinds closed on south and west-facing windows during the hottest part of the day (typically 12pm to 5pm in Spain during summer). Tiled floors are significantly cooler than carpet and dogs will naturally seek them out. Some veterinary behaviourists suggest that a fan directed at floor level can reduce the perceived temperature by 3°C to 4°C. Avoid leaving dogs in conservatories, cars, or any enclosed space that heats up rapidly.
5. Offer Frozen Treats
Frozen treats provide both hydration and a cooling effect. Freeze low-sodium chicken broth in ice cube trays, or blend dog-safe fruits such as watermelon (which is 92% water) or blueberries and freeze them in silicone moulds. These are particularly effective during the hottest part of the afternoon when outdoor activity is not advisable.
6. Never Leave Your Dog in a Parked Car
On a 25°C day, a car interior can reach 50°C within an hour. On a 30°C day, that rises to over 60°C, based on data reviewed in canine heat stroke literature. These are not edge cases; they are predictable outcomes of leaving an animal in an enclosed, sun-exposed space. In Spain, leaving an animal in conditions that endanger their health is an offence under the 2023 Animal Welfare Act (Ley 7/2023).
7. Provide Shade and Water Play Outdoors
If your dog spends time in a garden or outdoor space, ensure there is always a shaded area available. A paddling pool or splash mat gives dogs the option to cool themselves independently, which many will do naturally. Most veterinary experts agree that water play is one of the fastest passive cooling methods available, capable of reducing body temperature by 1°C to 2°C within a few minutes.
Should You Shave Your Dog in Summer?
This is one of the most common questions pet owners ask during warmer months. For single-coated breeds (Poodles, Maltese, Shih Tzus), a summer trim can help manage heat. For double-coated breeds (Huskies, Golden Retrievers, German Shepherds), most veterinary dermatologists and groomers advise against shaving. The undercoat acts as insulation in both directions, keeping cold out in winter and heat out in summer. Removing it disrupts this natural regulation, can increase the risk of sunburn, and may cause the coat to grow back with a different texture. Consult a qualified groomer or your vet before making significant changes to your dog's coat.
Keeping Puppies and Senior Dogs Safe
Puppies under six months have not yet developed full thermoregulation and can overheat faster than adult dogs. Senior dogs (generally over seven years for large breeds, over ten for small breeds, according to most veterinary age classification guidelines) may have underlying conditions such as heart disease or arthritis that make heat harder to manage and recovery slower. Both groups benefit from shorter walks, more frequent water breaks, and closer monitoring. If your senior dog is on medication, check with your vet whether any of their prescriptions affect heat tolerance, as some common drugs do.
Building a consistent daily routine that adapts to seasonal conditions is one of the most effective long-term strategies for protecting dogs of all ages. For more on why structure and predictability matter for your pet's overall wellbeing, read our guide on the benefits of routine for pets.
What to Do If Your Dog Overheats
If you suspect heat exhaustion or heat stroke, act immediately. Move your dog to a cool, shaded area and apply cool (not ice cold) water to their body, focusing on the neck, armpits, groin, and paw pads. Do not use ice or very cold water; rapid vasoconstriction can slow the cooling process and cause shock, according to VCA Animal Hospitals. Offer small sips of cool water if your dog is conscious and able to swallow. Contact your vet immediately, even if your dog appears to recover quickly, as internal organ damage may not be immediately visible and can develop over the following 24 to 48 hours.
Having a plan in place before an emergency happens makes a significant difference to outcomes. For a broader overview of pet health preparedness, see our article on how to make vet visits less stressful for your pet.
Final Thoughts
Keeping dogs cool in summer is largely a matter of awareness and small, consistent adjustments. Shift walks to cooler parts of the day, keep water accessible at all times, invest in the right gear for outdoor activity, and stay alert to the early signs of overheating. The risks are real and well-documented, but they are also highly preventable. With the right approach, summer can be a safe and enjoyable season for your dog.