Can I use iced water or ice packs?

Better not. Cool tap water combined with moving air cools effectively and predictably, while ice held against the skin causes local vasoconstriction and slows the release of deep heat. Ice also makes it impossible to tell how far the core temperature is really falling, because it cools the surface a lot and the centre very little.

My dog seems fine after ten minutes: do I still need the vet?

Yes. Apparent recovery is the most deceptive phase of heatstroke. Kidney complications, falling platelet counts and damage to the gut lining usually appear between twelve and seventy two hours later, when the animal is walking and eating as usual. A consultation and blood sample the same day catch them before they become symptomatic.

Can cats get heatstroke too?

Yes, less often than dogs but with equally severe cases. In cats the cause is almost always environmental: a carrier left in the sun, a closed conservatory, a room with no air exchange, a car journey without air conditioning. The sign not to ignore is open mouth breathing, which is never normal in a cat and should be treated as an emergency even with no other symptoms.

How long should I cool before leaving for the clinic?

Five to ten minutes on the spot is a good compromise when the clinic is twenty minutes away or more. If it is very close, cool for a couple of minutes and continue in the car. In no case does it make sense to stay at home cooling until the temperature is fully normal: the next phase needs fluids, oxygen and monitoring that do not exist at home.

Can I give a fever medicine or an anti inflammatory I have at home?

No. In heatstroke there is no reset thermostat as there is in fever, so antipyretics do not lower the temperature, and the most common human drugs are toxic to dogs and cats, damaging liver, kidneys and red blood cells. Any medication at this stage is decided by the vet after assessing hydration and kidney function.

Emergency procedures15 minLevel: IntermediateUpdated on July 28, 2026

Heatstroke: what to do in the first ten minutes

How to cool an animal with heatstroke, the temperature at which to stop, the mistakes to avoid and when to leave for the clinic.

Audience: Pet owners
Species: Dog, Cat
Scope: Valid everywhere

What you need before you start

Un termometro digitale per uso rettale e un lubrificante, tenuti dove puoi prenderli in pochi secondi
Acqua fresca corrente e un modo per muovere l'aria: un ventilatore, un cartone rigido o il climatizzatore dell'auto
Il numero della tua clinica e quello del pronto soccorso veterinario notturno salvati nel telefono
Un mezzo di trasporto pronto e una persona che possa guidare mentre tu resti accanto all'animale

Heatstroke is not a fever: it is hyperthermia from heat accumulation. The body produces or absorbs more heat than it can shed, and core temperature climbs until cells start to be damaged. The practical difference is huge, because fever needs a diagnosis while hyperthermia needs cooling, and it needs it straight away. Most of the damage is decided before the animal reaches the clinic, in the minutes when it is still at home or in the street. This guide covers what to do in the first ten minutes, where to stop cooling and what to report to the vet. First aid does not replace the consultation: it only gets a better animal through the clinic door than the one you found.

Recognising heatstroke in a few seconds

A dog panting after a run is not an emergency. It becomes one when panting no longer cools and signs of systemic distress appear. The typical picture builds in minutes: noisy continuous breathing, thick stringy saliva, brick red or purplish gums, an unsteady gait. In cats the key sign is different and much earlier: a cat breathing with an open mouth must always be treated as an emergency, even if it has not been running.

Violent panting that does not slow down even after a few minutes of rest in the shade.
Bright red, brick coloured or bluish gums, with thick sticky saliva.
Staggering gait, hind legs giving way, a fixed or absent stare.
Vomiting or diarrhoea, sometimes with traces of blood, during or right after exertion.
A cat breathing with its mouth open, noisy or not: a serious sign in any context.
Loss of consciousness, widespread muscle tremors or seizures: the most advanced stage.

The first ten minutes protocol

Stop everything and move the animal somewhere cool
End the walk, the run, the game. Move the animal into full shade on a cool surface, or into an air conditioned room or a car with the air conditioning already running. If it is too heavy to carry, create shade with whatever you have and start cooling on the spot.
Phone the clinic while you start cooling
Put the phone on speaker and do not interrupt the cooling to talk. Give the species, rough size, what the animal was doing, how many minutes the picture has lasted and the temperature if you have already measured it. Confirm where to take it and give your estimated arrival time.
Wet the body with cool running water
Use tap water, not iced water, and let it run continuously over the whole body. Concentrate on neck, armpits, groin, belly and paw pads, where vessels run close to the surface. A light continuous flow works better than a single bucket.
Move air over the wet coat
Water alone cools poorly: evaporation is what removes heat. Point a fan at the animal, open the windows, fan it with a stiff piece of cardboard. Cool water combined with moving air is the most effective method available at home.
Never leave soaked towels lying on the body
A drenched towel left in place warms up and becomes an insulating blanket that traps heat. If you use towels, change and rewet them constantly or, better, replace them with running water.
Take the rectal temperature every five minutes
If you have a digital thermometer, lubricate it and insert it a couple of centimetres, writing down the time and the reading. Without a thermometer do not stop: keep cooling and tell the vet that the temperature was not measured, rather than guessing it by eye.
Stop active cooling at 39.5 degrees
That is the stop threshold. Below it the temperature keeps falling on its own for a few minutes, and carrying on leads to hypothermia, which complicates the case instead of solving it. Towel the animal roughly dry and cover it with a light dry sheet.
Offer water only if the animal is alert
If it stands, recognises you and swallows, leave a bowl of cool water within reach and let it drink as much as it wants by itself. Do not pour water into the mouth and do not use syringes on a confused or unconscious animal: the risk of inhalation is real.
Leave for the clinic and keep cooling on the way
Cooling on the spot buys minutes, it does not replace the consultation. After five to ten minutes get moving, with the air conditioning aimed at the animal, a window slightly open and a second person still wetting it if the temperature remains high.

How far to cool and when to stop

Rectal temperature, meaning and immediate action
Rectal temperature	Meaning	Action
38.0 to 39.2 degrees	Normal resting range in dogs and cats	No active cooling, keep watching
39.3 to 40.0 degrees	Mild hyperthermia, common after intense activity	Shade, rest, water available, recheck after ten minutes
40.1 to 41.0 degrees	Heatstroke likely, especially with neurological signs	Start active cooling now and move to the clinic
Above 41.0 degrees	Emergency with risk of organ damage	Cool and go, phoning while on the road
39.5 degrees reached while cooling	Stop threshold for active cooling	Stop, dry the coat and cover with a light sheet

Normal values shift by a few tenths with time of day, activity and the stress of the measurement: a dog that has just arrived at the clinic can read a little higher from agitation alone. The number that really matters is the one taken at home before cooling, together with the time it was taken. Write down both: the vet will use that pair of data points to estimate how long the body stayed above the critical threshold.

Six things never to do

Do not place ice or freezer packs directly on the skin: extreme cold closes surface vessels and slows the release of deep heat.
Do not give human antipyretic drugs: paracetamol and ibuprofen are toxic to dogs and cats, and in heatstroke they are useless anyway, because there is no fever to bring down.
Do not force water into the mouth of an animal that is confused, vomiting or not fully conscious: it can end up in the airways.
Do not cover the animal with blankets during the drive, even if it shivers: shivering after cooling is expected and blankets push the temperature back up.
Do not postpone the visit because the animal looks normal again: late damage is the rule, not the exception.
Do not resume exercise in the following days without clearance from your vet: heat tolerance stays reduced for a long time after an episode.

The drive and the next seventy two hours

Hyperthermia damages kidneys, gut, liver and clotting with a delay that misleads owners. Over the following hours the vet typically checks hydration, kidney function, platelets and liver enzymes, and may ask to repeat the bloods after twenty four and forty eight hours. Knowing what to expect stops you from reading a second sample as an unexpected deterioration.

The exact time the first signs appeared and the time you started cooling.
The temperature measured before cooling and the temperature when you stopped, with both times.
What the animal was doing beforehand and the conditions: outside temperature, direct sun, humidity, surface.
Any vomiting, diarrhoea, seizures or loss of consciousness you saw, with how long each episode lasted.
Current medication, known conditions, recent surgery and an up to date body weight.
How much water the animal drank on its own after cooling, and whether it has urinated.

Prevention: the thresholds that matter

High risk situations and the practical rule
Situation	Why it is dangerous	Practical rule
Parked car with 22 degrees outside	The cabin can pass 40 degrees within an hour, even with windows cracked open	No stops with the animal on board, not even for five minutes
Tarmac in full sun with air at 25 degrees	The surface can exceed 50 degrees and burn the paw pads	Hold the back of your hand on it for seven seconds: if you cannot, neither can the animal walk on it
Relative humidity above seventy per cent	Evaporation from the tongue becomes inefficient and panting cools less	Move exercise to the early morning hours
Brachycephalic breeds, obese animals or thick coats	Heat loss is structurally reduced	Short walks, never running, with water always available
Animals over ten years old or under six months	Thermoregulation is less efficient at both ends of life	Change the timing and shorten the outing, not the air conditioning
Closed carrier in the sun or an exposed conservatory	It is the most common cause of heatstroke in cats	Check shade and ventilation every time you close a door

Prevention works when it becomes a fixed rule rather than a judgement made from scratch every time. Set a banned time window for exercise during the hot months, a water stop on the usual route and a routine check of the rooms you close. Those three measures together remove most of the scenarios that end in the emergency room.

Frequently asked questions

Can I use iced water or ice packs?: Better not. Cool tap water combined with moving air cools effectively and predictably, while ice held against the skin causes local vasoconstriction and slows the release of deep heat. Ice also makes it impossible to tell how far the core temperature is really falling, because it cools the surface a lot and the centre very little.
My dog seems fine after ten minutes: do I still need the vet?: Yes. Apparent recovery is the most deceptive phase of heatstroke. Kidney complications, falling platelet counts and damage to the gut lining usually appear between twelve and seventy two hours later, when the animal is walking and eating as usual. A consultation and blood sample the same day catch them before they become symptomatic.
Can cats get heatstroke too?: Yes, less often than dogs but with equally severe cases. In cats the cause is almost always environmental: a carrier left in the sun, a closed conservatory, a room with no air exchange, a car journey without air conditioning. The sign not to ignore is open mouth breathing, which is never normal in a cat and should be treated as an emergency even with no other symptoms.
How long should I cool before leaving for the clinic?: Five to ten minutes on the spot is a good compromise when the clinic is twenty minutes away or more. If it is very close, cool for a couple of minutes and continue in the car. In no case does it make sense to stay at home cooling until the temperature is fully normal: the next phase needs fluids, oxygen and monitoring that do not exist at home.
Can I give a fever medicine or an anti inflammatory I have at home?: No. In heatstroke there is no reset thermostat as there is in fever, so antipyretics do not lower the temperature, and the most common human drugs are toxic to dogs and cats, damaging liver, kidneys and red blood cells. Any medication at this stage is decided by the vet after assessing hydration and kidney function.

What to do next

Move the animal somewhere cool, phone the clinic on speaker and wet the body with cool running water while keeping air moving, concentrating on neck, armpits and groin. Stop active cooling at 39.5 degrees, write down temperatures and times, drive to the clinic while continuing to cool in the car, and have the animal examined the same day even if it looks fully recovered.