Heatstroke Kills Fast: What to Do in the First Ten Minutes

If your pet is panting in a frantic, ragged way, staggering, drooling thick ropes of saliva, vomiting, or has brick-red gums after any kind of heat exposure, this is an emergency. Get in the car and go to an emergency vet now, and phone them on the way so they can be ready for you. Do not wait to see whether it passes.

Heatstroke kills fast because it is not really about being uncomfortably hot. Once core temperature climbs past roughly 41°C (106°F), the gut lining starts to leak, the blood stops clotting properly, and the kidneys and brain take damage that can surface hours later — even after the animal looks better. That is why a dog who seems to recover in the back seat still has to be seen. Internal damage runs on its own clock.

The signs owners miss are the early ones. Panting that gets louder and more desperate instead of settling. A dog who stops and lies down halfway through a walk they normally love. Wobbly back legs. Gums that are bright red or brick coloured instead of bubblegum pink. Sudden vomiting or diarrhoea. Cats hide it better: a cat breathing with an open mouth is never normal, and is already an emergency.

Cooling on the way to the vet buys time. Use cool tap water — not ice water, not ice packs. Ice-cold water clamps the surface blood vessels shut, traps heat inside, and can trigger shivering that makes everything worse. Pour cool water over the whole body, especially the belly, the armpits and the groin, then get air moving over the wet coat: air conditioning on full, a fan, an open window. Wet plus airflow is what actually removes heat. A wet towel left lying on the body just becomes a warm blanket. Offer small sips of water only if your pet is fully conscious and wants them, and never pour water into the mouth of an animal who is dazed or collapsed.

Some pets are working with a much thinner margin. Flat-faced breeds — bulldogs, French bulldogs, pugs, boxers, Persian and exotic shorthair cats — cannot move air well enough to cool themselves, and they overheat in conditions other animals shrug off. So do seniors, overweight pets, thick double-coated northern breeds, puppies and kittens, and any animal with heart or airway disease. If that is your pet, treat moderate heat as if it were severe heat.

Two hard rules, and they are hard for a reason. Never leave a pet in a parked car: not for five minutes, not with the window cracked, not in the shade. The interior can climb 10 to 15°C above the outside air in under fifteen minutes, and it does not stop climbing. And test the ground with the back of your hand — if you cannot hold it there for seven seconds, it is too hot for paws. Walk at dawn or after dark instead, and carry water.

This is not a summer story for one country. Somewhere in the world it is a heatwave right now, and heatstroke arrives in clinics in every month of the year: in unventilated cars in mild weather, in dogs pushed too hard on a merely warm day, in animals shut on a balcony with no shade. If your gut says your pet is too hot, act as though you are right.