Cat heatstroke: the cool-down order and what makes it worse

Quick answer

Cats overheat differently from dogs. They rarely run themselves into trouble; they get shut into something. A greenhouse, a shed, a conservatory, an airing cupboard, a car, a carrier left in the sun, or a tumble dryer. The cat is usually found rather than watched, so the first thing an owner sees is already an advanced stage.

The order matters. Get the cat out of the heat, wet the coat down to the skin, and get air moving over it. Then keep doing that while someone else phones the vet. Cooling on the way in is better than cooling on arrival, and a cat that looks recovered still needs to be seen.

A towel, a fan and a bowl of cool water do more in the first ten minutes than anything else in the house.

• Panting in a cat is never normal. It is not the equivalent of a dog panting.
• Wet the coat to the skin, especially the belly, armpits and groin. A dry-looking wet cat is not being cooled.
• Do not immerse a conscious cat in water. Cats panic, and the struggle generates more heat than the water removes.
• Never give paracetamol or any human medicine. Paracetamol kills cats.
• Every heat episode needs a vet, even a cat that seems fine an hour later.

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Never give a cat paracetamol, ibuprofen, aspirin, or any other human painkiller or fever medicine.

Cats lack the liver pathway that safely processes paracetamol. A single tablet causes the blood to lose its ability to carry oxygen and destroys liver tissue, and the signs, which include facial swelling, brown gums and laboured breathing, are frequently mistaken for the heat problem the owner was trying to treat. There is also no rationale for these drugs here: heatstroke is not a fever. The body is trying to hold its normal temperature and failing, not deliberately raising it.
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Decide in 60 seconds

Why cats are different

The domestic cat descends from a desert species and is well built for dry heat in one respect: it conserves water superbly and concentrates its urine. What it does not have is a good way to dump heat.

There is no meaningful whole-body sweating. There is a small amount from the paw pads, which is why a stressed cat leaves damp prints on a consulting table. The main route is grooming: the cat licks saliva onto the coat and lets it evaporate. That works in dry air and at moderate loads, and it fails quickly in humid air or when the cat is genuinely hot.

Panting is the reserve. A dog pants routinely; a cat panting has run out of other options, or is in respiratory distress from something else entirely. Either way it is a reason to act.

The behaviour compounds the physiology. Cats actively seek warm places and will tolerate a great deal of heat before moving. A cat that has crept into a greenhouse or an airing cupboard is not making a mistake by its own reckoning until it is too late to leave, and if the door has closed behind it, leaving is not an option at all.

Which cats are already at a disadvantage

Flat-faced breeds.

Persians, exotics, Himalayans and increasingly extreme British shorthairs have compressed nasal passages. The nose is where the air is conditioned and where much of what limited evaporative cooling exists happens, and a narrowed airway also means more work to breathe.

Very dense or long coats.

Maine coons, Norwegian forest cats, ragdolls, Persians and any cat carrying a matted undercoat. Mats in particular trap a still layer of hot, humid air against the skin and stop water reaching it, which makes them a cooling problem as well as a skin problem.

Overweight cats.

Fat insulates and adds work. This is the risk factor that owners can change.

Cats with heart disease.

Hypertrophic cardiomyopathy is common in cats and frequently silent until something stresses the system. Heat, a struggle, and the fluid shifts that follow are exactly that stress.

Hyperthyroid cats.

A raised metabolic rate means more heat produced and less tolerance of a warm day, often in a cat that is already thin and elderly.

Kittens and seniors.

Both regulate temperature less well, and seniors often cannot leave a hot spot quickly.

Any cat in a carrier.

A carrier in a car, in a sunny window, or in a waiting room is a small unventilated box. Cats have died in carriers on short journeys.

The cool-down order

The order is deliberate. Each step is worth less if the one before it has not been done.

One: remove the heat source.

Get the cat out of the hot space and into the coolest room in the house, ideally one with a tiled or wooden floor. Put it on the floor rather than on a lap or a bed, because floors are cooler and because a collapsing cat should not be held up.

Two: get air moving.

Open a window on the shaded side, or set a fan up so it blows across the cat rather than directly into its face. Air movement is what makes the water work, and a fan on a dry cat does very little.

Three: wet the coat, to the skin.

This is the step people get wrong. Cat fur sheds water. Pouring a jug over the back leaves you with a wet-looking cat and a dry animal.

Use cool tap water, not iced. Work it into the coat with your hands, parting the fur as you go. Concentrate on the underside: the belly, the armpits, the groin and the inside of the thighs, where the skin is thin and large blood vessels run close to the surface. Wet the ear flaps, the paws and the face gently with a damp cloth. Keep going, keep re-wetting, and do not let the coat dry off.

Four: cool packs, used correctly.

A cool pack or a bag of frozen vegetables wrapped in a thin damp towel can be tucked against the groin or armpit. Never place anything frozen directly against skin, and never rely on cool packs instead of wetting the coat.

Five: offer water, never force it.

A conscious, alert cat may drink and should be allowed to. Do not syringe water into the mouth of a cat that is collapsed, dazed or vomiting. It goes into the lungs.

Six: ease off as the cat improves, and travel.

Cats are small and cool faster than dogs, so it is easy to overshoot into hypothermia. As the cat becomes brighter and the breathing settles, stop actively wetting, pat off the excess, and travel with the car air conditioning on and the carrier out of direct sun. Tell the vet exactly when you started and stopped cooling.

Do not immerse a conscious cat.

This is a genuine difference from the advice for dogs. Most cats fight being put into water, and a struggling cat generates heat, risks inhaling water, injures itself and injures you. Continuous dousing plus airflow achieves the same cooling without the fight. A cat that is unconscious should be cooled with running water rather than submerged, so that the airway stays clear.

Gum colour is the fastest check you have. Brick red is heat. Pale, grey or blue is circulatory failure and means go immediately.

The signs, in the order they arrive

Restlessness and a search for cool surfaces come first. The cat stretches out flat on tiles or in a bath, lying on its side with the legs extended to expose as much surface as possible, and grooms heavily. Owners often read the grooming as normal behaviour. It is a cooling attempt.

Then the breathing changes. Faster, then open-mouthed, then frank panting with drooling. The tongue and gums go bright red as blood is shunted to the surface, and the saliva becomes thick.

Then the gut goes. Vomiting and diarrhoea, sometimes with blood.

Then the nervous system. Wobbliness, a glazed or vacant look, apparent blindness, tremors, seizures and collapse.

Then circulation fails. Gums move from brick red to pale, grey or blue, and small pinpoint bruises may appear on the gums or the belly, which reflects a clotting failure.

A cat can be found already at the fourth or fifth stage, because the earlier ones happened behind a closed door.

What else looks like this

Heart disease and pleural effusion.

A cat breathing with an open mouth, sitting hunched with its elbows out, and reluctant to lie down may have fluid around its lungs rather than heat injury. This is a critical emergency in which handling itself can be fatal. If there is no heat exposure, do not wet the cat and do not attempt an examination. Put it in a carrier with minimal fuss and go.

Feline asthma.

Coughing, wheezing, and a crouched posture with the neck extended. Usually a history of episodes.

Permethrin poisoning.

A dog flea product applied to a cat, or a cat that has groomed a recently treated dog. It causes muscle tremors, twitching, seizures and a rising body temperature that looks exactly like heatstroke. Cooling is part of the treatment, but so is a specific antidote and intensive care, and the history is what makes the diagnosis. Mention any flea product used on any animal in the house.

Pain and stress.

A cat that pants after a car journey or a frightening event is not necessarily overheated. It should still settle within a short time in a cool quiet place, and if it does not, it needs to be seen.

Anaemia and severe illness.

Pale gums with rapid breathing and weakness in a cat with no heat exposure.

What never to do

Do not use ice-cold water, ice baths or a freezer for a small cat. Cool tap water applied continuously is enough, and it does not risk overcooling an animal this size.

Do not drape wet towels over the cat and leave them. Within minutes they reach the cat's own temperature and become an insulating layer that blocks airflow. Either keep replacing them or, better, keep the coat wet and exposed.

Do not rub alcohol or surgical spirit on the paws. It is absorbed and it is toxic, and the cooling is negligible.

Do not force-feed water or food.

Do not shave a heat-stressed cat as an emergency measure. Clipping a matted coat has a place, calmly and later, but wrestling a distressed cat with clippers now makes everything worse.

Do not put a cat in a bath or a sink and hold it there.

Do not use a hairdryer on a cool setting to move air. The noise terrifies most cats and the airflow is too narrow to be useful.

Do not delay the vet because the cat seems better. This is the mistake that costs cats their kidneys.

The days afterwards

Heat injures the gut lining, the kidneys, the liver, the brain and the clotting system, and the damage becomes apparent over the following one to three days rather than in the first hour.

Watch for a cat that stops eating, is not producing urine in the tray, becomes yellow around the gums or eyes, has bloody diarrhoea, bruises easily, is disorientated, or simply stays quiet and hidden. Any of those means going back immediately.

This delayed pattern is why veterinary teams admit and monitor cats after significant heat episodes rather than sending them home once the temperature is normal. Blood tests during that window catch acute kidney injury while it is still treatable.

Preventing it

Check sheds, greenhouses, garages, conservatories and outbuildings before you close the door, every time. Cats are inside them more often than owners believe.

Check the tumble dryer and the washing machine before running them.

Never transport a cat in a car boot, never leave a carrier in a parked car, and never put a carrier in direct sun even indoors.

In a heatwave, close curtains on the sunny side, leave interior doors open so the cat can choose, provide a tiled or stone floor area, and put out several shallow water bowls in different rooms, because cats drink more when water is not next to the food.

Keep long coats groomed through the summer. Mats are a cooling problem.

Keep the cat lean. It is the risk factor with the biggest return.

Know your own cat's baseline breathing. Count the breaths of a sleeping cat occasionally so you know what normal looks like for that animal.

When to get help

Go immediately, cooling as you go, for collapse, seizures, disorientation, vomiting or diarrhoea after heat exposure, gums that are pale, grey, blue or bruised, or any cat found unresponsive in a hot enclosed space.

Go the same day for any cat that has been panting, any cat found shut in a hot space even if it appears well, and any cat that is quieter than normal after a hot day.

Go immediately without cooling, and with as little handling as possible, for a cat breathing hard with no heat exposure. That is a chest emergency and the handling itself is a risk.

Bring the timeline: where the cat was, for how long, when you found it, what you did and when you started and stopped cooling, whether it vomited, whether it has urinated since, and what flea or worm products have been used on any animal in the house in the past few weeks.

Recovery is a cat that is eating, drinking, using the tray normally and breathing quietly with its mouth closed.