The first warm day of the year always catches dog owners off guard. The walk you've done a hundred times in winter suddenly becomes a different walk in June. Your dog seems fine. They're trotting along, tail up, sniffing things. And then, sometimes very suddenly, they're not fine at all.
Heat stress in dogs is one of those problems that goes from invisible to serious in minutes. Unlike humans, dogs can't sweat through their skin — they cool down almost entirely through panting and through the pads of their feet. On a hot day, those two systems can't keep up, and a dog can go from "a bit warm" to a veterinary emergency faster than most owners expect.
The good news is that heat stress is almost entirely preventable once you know what to watch for. Here's what's actually happening, the warning signs in order of severity, and how to keep your dog cool through European summers — which are getting hotter every year.
Why dogs overheat so easily
Dogs and humans handle heat very differently, and most of the difference works against the dog.
No sweat glands across the body. You cool down by sweating across your whole skin surface, which evaporates and pulls heat away. Dogs have sweat glands only in their paws — a tiny fraction of the surface area. So that cooling pathway is minimal.
Panting is the main cooling system. A dog cools down primarily by panting — rapid breathing that evaporates moisture from the tongue and respiratory tract. This works well in mild conditions but becomes much less effective when air temperature rises above body temperature, or when humidity is high enough that water can't evaporate easily.
A fur coat doesn't come off. Your dog can't unzip their coat when it gets hot. Even short-haired dogs carry meaningful insulation. Double-coated breeds (huskies, retrievers, shepherds) carry a lot more.
They run hotter than you to start with. A dog's normal body temperature is around 38–39°C — already higher than yours. The margin between healthy temperature and dangerous temperature is smaller than people realise.
Add it all together and a dog on a 25°C day is doing what you'd be doing on a 35°C day. On a 30°C day, they're already in heat-stress territory before you've even broken a sweat.
The warning signs, in order
Heat stress isn't binary. It progresses through stages, and recognizing the early stages is what keeps it from becoming the late ones.
Stage 1: Heat stress (still safe, time to act)
- Heavier panting than usual for the activity level
- Seeking shade unprompted
- Slowing down on the walk, lagging behind
- Wanting to lie down on cool surfaces (tile, grass, stone)
- Increased thirst
This is the stage where you should already be acting. Move to shade, offer water, let the dog rest. Don't push through with "just a bit further."
Stage 2: Heat exhaustion (serious, act immediately)
- Very heavy, rapid panting with tongue hanging far out
- Bright red gums and tongue
- Drooling more than normal, often thick saliva
- Weakness or stumbling
- Refusing to walk further or lying down and not wanting to get up
- Body temperature 39.5–41°C
At this stage you need to actively cool your dog down. Get them somewhere shaded immediately. Offer cool (not ice-cold) water. Wet their paws, belly, and the inside of their thighs — those areas have the most blood vessels close to the surface. Don't pour water on the back of a thick-coated dog; the fur holds heat in.
Stage 3: Heatstroke (medical emergency)
- Vomiting or diarrhea (often bloody)
- Confusion, glassy eyes, unsteady walking
- Collapse or seizures
- Pale or blue-tinged gums
- Body temperature above 41°C
This is a life-threatening emergency. Start cooling the dog immediately with cool water on the paws, belly, and groin, and get to a vet at the same time — don't wait until they're cooled down to go. Heatstroke causes internal damage that needs veterinary care even after the dog appears to recover. A dog who has had heatstroke once is more susceptible to it for the rest of their life.
The situations that catch owners out
Heatstroke rarely happens in the obvious situations — most owners know not to leave their dog in a parked car. It happens in less obvious ones:
The walk that started cool. You head out at 8am when it's 18°C. By 10am when you're heading home, it's 27°C and your dog is in trouble. Plan walks for early morning or evening on hot days, and shorten them.
Hot pavement. Asphalt absorbs heat all day. Even after the air cools in the evening, the ground can stay much hotter — sometimes 50–60°C or more. Walking on it burns paws and radiates heat back at your dog's belly. Test rule: hold the back of your hand on the pavement for seven seconds. If you can't, your dog shouldn't be walking on it.
The garden. A dog in a sunny garden with no shade can overheat without ever leaving the house. Make sure there's always shaded space available and water within reach.
Indoors on hot days. Most European homes don't have air conditioning. An apartment can climb to 28–30°C indoors during a heatwave, especially on top floors. Your dog can't unzip their coat or escape to a cooler room if all the rooms are warm.
The car, even briefly. A car parked in 25°C sun reaches 40°C inside within 10 minutes, 50°C within 30. "Just running into the shop" is enough time for permanent damage. If the dog has to be in the car, it has to be with the engine on and air conditioning running.
Dogs at higher risk
Some dogs handle heat much worse than others. If yours falls into one of these categories, be extra cautious:
- Brachycephalic (flat-faced) breeds. French bulldogs, pugs, boxers, English bulldogs, Pekingese, shih tzus. Their shortened airways make panting less effective at cooling. These dogs are at high risk of heatstroke even in moderate heat.
- Double-coated and Nordic breeds. Huskies, malamutes, samoyeds, Bernese mountain dogs, golden and Labrador retrievers. Built for cold, struggle in heat.
- Senior dogs. Older dogs regulate temperature less efficiently and tire faster.
- Puppies. Their cooling systems aren't fully developed.
- Overweight dogs. Extra mass to cool, often paired with lower fitness.
- Dogs with underlying conditions. Heart disease, respiratory issues, and laryngeal paralysis all increase risk.
What actually helps
Keeping a dog cool through summer comes down to a few practical things:
Walk timing
The single biggest thing you can change. Walks before 8am and after 8pm in summer; short or skipped at midday. Yes, this is annoying. It's also what works.
Constant water access
Multiple water sources at home. A bottle on every walk. Travel water bottles with built-in drinking troughs make this much easier than carrying a bowl. Refill at any tap or fountain.
Shade and ventilation
Make sure there's always shaded space available outdoors. Indoors, keep curtains closed during peak sun and consider a fan in the room where your dog rests.
A cooling mat
This is the single most effective indoor heat tool we sell. Our ChillZone Dog Cooling Mat uses a pressure-activated gel layer that cools instantly when your dog lies down on it — no electricity, no refrigeration, no water needed. The gel absorbs heat from the dog's body and dissipates it, then recharges itself when the dog gets up.
We offer it in three sizes (50×40 cm, 62×50 cm, 70×55 cm) for different breed sizes. Most dogs figure it out within a few minutes of being introduced to it — once they lie down once and feel the temperature difference, they actively seek it out on hot days.
Best places to put one: where your dog already rests during the day. In the living room. In their crate. On the patio in the shade. In the car on long summer drives.
Avoid hot surfaces
The pavement test mentioned earlier. Stick to grass, shaded paths, and dirt trails on hot days. Avoid sand on beaches in midday — it gets hot enough to burn pads.
Don't shave double-coated breeds
Counterintuitive, but important. A double coat insulates against heat as well as cold — it traps a layer of air that buffers the dog from outside temperature. Shaving it removes that buffer and exposes the skin to direct sun. Brushing out the loose undercoat in spring is the right answer for these breeds, not clippers.
Wet down the paws and belly
Quick way to cool a hot dog. Wet the paws and the belly with cool (not ice-cold) water. These are where the blood vessels are closest to the surface and where cooling has the biggest effect. Don't soak the whole coat — wet fur insulates and can actually slow cooling.
A note on European summers
If you live anywhere in central or southern Europe, summer is getting hotter. Heat domes that were once unusual are becoming regular features of July and August. Even Scandinavian summers, traditionally cool, are seeing more 30°C+ days each year.
This matters because the gear and habits that worked five years ago might not be enough now. A dog that handled summers in Stockholm in 2020 might be struggling in 2025. Worth checking your routine — and your dog — against current conditions, not memories.
The short version
Watch for early signs: heavier panting, seeking shade, slowing down. Act before those signs become serious ones. Walk in cool hours. Always carry water. Provide a cool resting surface indoors. Test the pavement before letting your dog walk on it. For dogs at higher risk — flat-faced breeds, double-coated breeds, seniors — be extra cautious.
Heat stress is one of those problems that's invisible until it isn't. The dogs that come through summer well are the ones whose owners stay one step ahead of it.
Midello designs Scandinavian dog gear for active dogs and the people who walk them. Our ChillZone Dog Cooling Mat is designed for exactly this — instant cooling on hot days, no electricity needed. Available in three sizes for small to large dogs. Shipped across the EU, free returns within 30 days.
