Dogs don’t die just in hot cars. The bigger risk is the walk you already planned today.
A study of 905,543 dogs found most heat-related illness happened during ordinary exercise, not in a parked car. Here is what the research actually says, and the three things you control.
If you read one paragraph, read this one. The most common trigger for canine heatstroke is exertion on a warm day, not a locked car. In the largest study of its kind, one in seven dogs treated for heat-related illness died from it. The three levers you actually control are when you walk, how much water is available, and whether your dog has a cool surface to dump heat onto afterwards.
The hot car is the famous risk, not the common one
Almost every dog owner knows not to leave a dog in a parked car. That message worked. The problem is that it is now the only heat message most owners have ever heard.
Researchers at the Royal Veterinary College reviewed the anonymised clinical records of 905,543 dogs and found that the majority of heat-related illness cases were exertional, meaning they happened while the dog was moving. Playing. Walking. Doing the thing you do every single day without thinking about it. The paper is literally titled Dogs Don’t Die Just in Hot Cars.
A parked car is an obvious danger you avoid. A 3pm walk in July is an invisible one you schedule.
Source: Hall et al., Animals (2020), "Dogs Don’t Die Just in Hot Cars"
One in seven did not survive it
In the 2016 VetCompass cohort, the event fatality rate for heat-related illness was 14.18%. That is roughly one in seven dogs who were treated for it. A separate 2024 study looking at UK emergency clinics specifically found an even higher fatality rate in that caseload, at 26.56%.
Heatstroke is not a bad afternoon your dog sleeps off. Once core temperature runs away, the damage is to organs, and it is fast.
Source: Hall et al., Scientific Reports (2020)
Why panting quietly stops working
Dogs do not sweat the way people do. They shed heat mostly by panting, which is essentially evaporative cooling across the tongue and airway, and by transferring heat from their body into whatever surface they are lying on.
Both of those get worse in exactly the conditions where you need them most. When the air is already warm and humid, evaporation slows down, so panting returns less cooling per breath. And when every surface in the house has soaked up the day’s heat, lying down stops helping. Your dog is still trying to cool. The tools just stopped working.
This is also why an air-conditioned room is not the whole answer. Cooled air helps the panting side. It does nothing for the surface your dog is lying on if that surface is already at body temperature.
The three things that actually lower the risk
1. Move the walk. Early morning and after dark. Not midday, not late afternoon. If the pavement is uncomfortable on the back of your hand for seven seconds, it is too hot for paws and too hot for a walk.
2. Water available before, during and after. Not just when you get home. Dogs under two years old had the highest risk of exertional heat illness in the data, which likely reflects how hard young dogs push themselves. They will not self-regulate. You have to.
3. Give them a cool surface to unload into. This is the one most people skip. After exertion, a dog needs somewhere to dump heat. A pressure-activated cooling mat works by conduction: your dog lies down, the gel absorbs body heat, and it keeps pulling heat away without refrigeration, water or power. It is the passive half of cooling, and it is the half a fan or an AC unit does not do.
What we make for this
Pawden makes self-cooling mats and beds for exactly this. No water, no refrigeration, no power. Your dog lies down and the gel does the work.
Signs you should not wait on
Heavy or frantic panting that does not settle, bright red or very pale gums, thick drool, wobbliness or stumbling, vomiting or diarrhoea, confusion, collapse.
If you see these, start cooling immediately with cool (not ice-cold) water and get to a vet. Cooling on the way matters. A cooling mat is for prevention and recovery. It is not treatment for a dog in crisis, and nothing on this page is a substitute for veterinary care.
Common questions
Is a cooling mat better than just running the air conditioning?
They do different jobs. Air conditioning cools the air your dog breathes, which helps panting work better. A cooling mat cools by direct contact, which is how dogs shed heat into a surface. Doing both is better than either alone, and the mat keeps working during a power cut or in the car.
Does it need to go in the freezer?
No. Pressure-activated gel mats work on contact. Your dog lies down, the gel absorbs body heat and disperses it. They recharge on their own after about 15 to 20 minutes off the mat.
What if my dog will not use it?
Most dogs find it themselves within a day or two because it genuinely feels better. If yours is cautious, put it where they already choose to lie in hot weather, usually tile or a doorway, rather than trying to move them somewhere new.
Which breeds are at highest risk?
In the VetCompass data, compared with Labrador Retrievers: Chow Chow 17x, Bulldog 14x, French Bulldog 6x, Dogue de Bordeaux 5x, Greyhound 4x, Pug, Cavalier King Charles Spaniel, Golden Retriever and Springer Spaniel all around 3x. Dogs carrying extra weight and dogs over 50kg were also at higher risk.