It's the start of August, and the thermometer shows no sign of backing down. German summers are not what they used to be. Europe is the fastest warming continent on Earth, heating at roughly twice the global average since the 1980s, with heatwaves growing longer, hotter and more frequent [1]. For us, a hot week means shade, a cold drink, and fanning ourselves with the electricity bill while quietly wondering why air conditioning never quite caught on in Germany. For our dogs and cats it can mean a genuine, sometimes fatal, medical emergency. Pets cannot sweat the way we do; they shed heat mainly by panting, which is far less efficient, and they cannot simply take off a layer or open a window [2]. This guide explains what actually causes heat emergencies, how to spot one early, what to do in the crucial first minutes, and how German law treats the classic hot-car situation.
Why pets overheat so easily
Dogs and cats regulate temperature poorly compared with humans. With very limited ability to sweat, they rely on panting and on radiating heat from their bodies, and both become useless once the surrounding air is nearly as warm as they are [2]. Some pets are far more vulnerable than others. The Royal Veterinary College lists the highest-risk groups as overweight animals, flat-faced (brachycephalic) breeds such as Pugs, Bulldogs and French Bulldogs, and Persian cats, animals with thick coats, the very old and very young, and any pet with existing airway, lung or heart disease [2]. For flat-faced breeds the problem is structural: the same squashed airway that makes them snore makes it physically hard to pant enough to cool down.
Cats deserve a special note. As descendants of desert animals they tolerate warmth better than dogs and rarely make headlines, but they are not immune, and their signs are more subtle [2]. One point every cat owner should know: a cat that is panting like a dog is not "just hot," it is showing an abnormal and serious sign that warrants immediate cooling and a call to the vet.
The biggest myth: it is not just hot cars
Ask anyone about pets and heat and they will picture a dog in a parked car. That danger is real, but the data tell a more surprising story. In the largest study of its kind, the VetCompass programme analysed more than 900,000 UK dogs [3] and found that, among cases with a known trigger, only 5.2 percent of heat-related illness came from being confined in a vehicle. The overwhelming majority, 74.2 percent, was exertional, brought on by physical activity, while 12.9 percent came from a hot environment such as a warm room or garden [4]. Most striking of all, of the exercise-triggered cases where the activity was recorded, 67.5 percent happened after nothing more strenuous than a walk [4].
The practical lesson is blunt: on a hot day, the single most dangerous thing most owners do is exercise their dog. A midday walk in July is a bigger statistical risk than the car. This does not let the car off the hook, but it should change where you focus your caution.
The hot car, and what German law says
A parked car in summer becomes an oven with terrifying speed. The German automobile association ADAC has measured interior temperatures approaching 40°C after just ten minutes when it is only 28°C outside, and climbing above 50°C within half an hour and towards 60°C within about ninety minutes even when the outside temperature is below 30°C [5]. Cracking a window open barely slows this rise [5]. Above roughly 40°C a dog can suffer lasting organ damage, and beyond about 45°C there is an immediate risk of death [5]. ADAC's advice is unambiguous: between spring and autumn, never leave a dog alone in the car, not even for a few minutes [5].
German law backs this up. The Animal Welfare Act (Tierschutzgesetz) forbids causing an animal pain, suffering or harm without good reason, and leaving a dog in a heating car can be prosecuted as an administrative offence carrying a fine of up to €25,000 [6]. If you come across a dog in distress in a locked car, the recommended steps are to try to find the owner (for example by having them paged in a nearby shop), to gather evidence such as photos and witnesses, and to call the police on 110 [5][6]. Breaking a window to free an animal in acute danger can be justified under the legal principle of necessity (rechtfertigender Notstand, §34 StGB), but because the situation and any liability can be complex, calling the police or fire service first is the safest course wherever time allows [6].
Know the warning signs
Heatstroke can escalate from "a bit hot" to life-threatening within minutes, so recognising it early matters enormously. The signs are similar in dogs and cats, though in cats they are often quieter [2].
Early signs:
- Heavy panting that progresses to noisy or distressed breathing (in cats, any panting at all)
- Restlessness or agitation, pacing, desperately seeking shade or water
- Drooling, sometimes thick and ropey
- Bright red gums or tongue
- A racing heartbeat
- Vomiting or diarrhoea
First aid: "cool first, transport second"
This is the part where old advice can cost lives, so it is worth being precise. Current best-practice veterinary guidance is to cool the animal down straight away, before rushing to the clinic, an approach summed up as "cool first, transport second" [2][7]. The reasoning is simple: the longer the body temperature stays high, the more damage is done, and the odds are stark. RVC researchers found that 97 percent of dogs treated for mild heat-related illness survived, compared with only 43 percent of those that reached the severe stage, so stopping the temperature rise early is what saves lives [7][8].
What to actually do [2][7]:
- Move the pet to shade or a cool, well-ventilated spot, ideally with a fan or air conditioning.
- Get water onto them fast, using water that is cooler than the animal. For young, healthy dogs, cold-water immersion (for example a paddling pool or dousing with a hose) is effective and appropriate. For older dogs, cats, or pets with health problems, use the evaporative method: pour cool water over them continuously and combine it with moving air from a fan or breeze.
- Do not use ice-cold water. It can constrict the skin's blood vessels and trigger shivering, both of which slow cooling down rather than speed it up.
- Offer small sips of water to drink, but never force it.
- Then call your vet and go in, even if your pet seems to recover. Serious internal effects can appear hours later.
One sobering finding shows how much room there is to improve: in the VetCompass cooling study, only 21.7 percent of dogs brought to vets with heatstroke had been actively cooled beforehand, and of those, more than half were cooled with the outdated wet-towel method, which is far less effective than immersion or evaporative cooling [9]. Wet towels draped over a dog are better than nothing, but they are not the goal.
Prevention: the part that actually keeps them safe
Almost every heat emergency is preventable. During hot spells:
- Reschedule exercise. Walk dogs in the early morning or late evening, and on genuinely hot days skip the walk altogether. A missed walk never hurt a dog; a midday one can kill [4].
- Do the pavement test. Asphalt and sand can burn paw pads. Hold the back of your hand against the ground for a few seconds; if it is too hot for your hand, it is too hot for their paws [2].
- Shade and water, always. Ensure constant access to shade and fresh water indoors and out; a few ice cubes help keep bowls cool, and cats often drink more from several bowls placed around the home [2].
- Never leave a pet in a car or a hot room. That includes conservatories and glassed-in balconies, which heat up just like cars [2][5].
- Help them cool at home. Cooling mats, damp towels to lie on, a fan, and good ventilation all help. Keep blinds closed against midday sun.
- Mind the high-risk pets especially. Flat-faced breeds, overweight animals, seniors and pets with heart or airway disease need extra caution and much lighter activity [2].
- Groom appropriately. Regular grooming of thick or matted coats (as advised for the breed) helps heat escape [2].
The bottom line
Heat is one of the few emergencies that is almost entirely in your hands. The science points to three simple habits: do not exercise pets in the heat, never shut them in a car or hot room, and if overheating starts, cool them immediately with water and call your vet rather than driving first. As European summers keep breaking records [1], these are no longer occasional precautions but a normal part of caring for a dog or cat in Germany. When in doubt, cool them down and pick up the phone.
This article is for general information and is not a substitute for veterinary advice. Heatstroke is a medical emergency: if you suspect it, begin cooling immediately and contact your veterinarian or the nearest emergency veterinary service (Tierärztlicher Notdienst) at once.
References
- Copernicus Climate Change Service (C3S), European Centre for Medium-Range Weather Forecasts. European State of the Climate 2024 (Europe as the fastest-warming continent; increasing heatwave frequency and intensity). https://climate.copernicus.eu/esotc/2024
- Royal Veterinary College. Heatstroke in dogs and cats: prevention, symptoms and first-aid tips for pet owners (fact file). https://www.rvc.ac.uk/small-animal-vet/teaching-and-research/fact-files/heatstroke-in-dogs-and-cats
- Hall EJ, Carter AJ, O'Neill DG. Incidence and risk factors for heat-related illness (heatstroke) in UK dogs under primary veterinary care in 2016. Scientific Reports, 2020;10:9128. doi:10.1038/s41598-020-66015-8. https://www.nature.com/articles/s41598-020-66015-8
- Hall EJ, Carter AJ, O'Neill DG. Dogs Don't Die Just in Hot Cars - Exertional Heat-Related Illness (Heatstroke) Is a Greater Threat to UK Dogs. Animals, 2020;10(8):1324. doi:10.3390/ani10081324. https://www.mdpi.com/2076-2615/10/8/1324
- ADAC. Autofahren mit Hund bei Hitze (car interior temperature measurements; never leave a dog alone in the car). https://www.adac.de/gesundheit/gesund-unterwegs/reisen-mit-dem-tier/hund-auto-hitze/
- Tierschutzgesetz (German Animal Welfare Act), §1 and §18, and the Tierschutz-Hundeverordnung §8 (duty to ensure fresh air and appropriate temperatures for unsupervised dogs, for example in vehicles). https://www.gesetze-im-internet.de/tierschg/
- Royal Veterinary College / VetCompass. The RVC urges owners of hot dogs to "cool first, transport second" (2023; includes 97% vs 43% survival for mild vs severe heat-related illness). https://www.rvc.ac.uk/vetcompass/news/the-rvc-urges-owners-of-hot-dogs-to-cool-first-transport-second
- Hall EJ, Carter AJ, Chico G, Bradbury J, Gentle LK, Barfield D, O'Neill DG. Risk Factors for Severe and Fatal Heat-Related Illness in UK Dogs - A VetCompass Study. Veterinary Sciences, 2022;9(5):231. doi:10.3390/vetsci9050231. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9144152/
- Hall EJ, Carter AJ, Chico G, et al. Cooling Methods Used to Manage Heat-Related Illness in Dogs Presented to Primary Care Veterinary Practices during 2016-2018 in the UK. Animals, 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10385239/
