What are the signs of heatstroke in dogs?

Heavy panting that does not settle, excessive drooling, bright red or very pale gums, vomiting, diarrhoea, wobbliness, collapse or seizures. It can develop within minutes in a hot car or after exercise in heat.

Should I use ice on an overheating dog?

No. Use cool (not ice-cold) water on the body, wet towels and fanning. Offer small drinks if they are conscious. Phone your vet while cooling. Ice baths can worsen shock.

Which dogs are most at risk?

Flat-faced breeds, overweight dogs, thick-coated breeds, puppies, elderly dogs, and those with heart or airway disease. Any dog can overheat in a hot car or after strenuous exercise in heat.

When is it too hot to walk a dog in the UK?

Many UK vets cut exercise for sensitive dogs from around 20°C and skip normal walks in the mid-20s. Always do the five-second pavement test. Use the PETHEALTH+ walk-temperature checker as a sense-check, then watch your dog.

Dog Health

Dog Heatstroke UK

Published 1 June 2026Last updated 13 August 20264 min read

Quick answer

Heatstroke is an emergency. Move your dog to shade, cool with tepid water and wet towels, offer small drinks, and phone your vet immediately while you keep cooling. Do not ice-bath. If your practice is closed, use the PETHEALTH+ out-of-hours directory. Prevention: no hot cars, no midday walks — check is it too hot to walk? first.

Key takeaways

Heatstroke is a same-day emergency — heavy panting, bright red gums, vomiting, wobbliness or collapse need tepid cooling and a vet, now.
Cool with tepid water and wet towels — never an ice bath; sudden chilling can worsen shock.
Phone your vet while you cool. Prevention: no hot cars, no midday tarmac, and use the walk-temperature checker before you set off.

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How heatstroke happens

Dogs cool mainly by panting. They have few sweat glands. When heat from air, sun, hot ground and exercise exceeds what panting can dump, core temperature rises. UK veterinary charities treat this as a minutes-not-hours problem in cars and after ball games on hot days.

Common UK triggers:

Being left in a car — even with windows cracked, even on a cloudy day
Midday walks on tarmac
Overexertion — fetch, running beside a bike, agility in sun
No shade or water in a garden or conservatory
Humidity, which makes panting less effective

This page is first aid and when to go. For walk timing and the pavement test see can I walk my dog in hot weather? and the walk temperature checker. Heavy panting on a cool day is a different problem — see why is my dog panting heavily?.

Who is at higher risk?

Any dog can overheat. Risk is higher in:

Group	Why
Flat-faced (brachycephalic) breeds	Narrow airways limit cooling
Overweight dogs	Extra insulation, harder work to move
Thick coats	Heat stays in the coat
Puppies and seniors	Less efficient temperature control
Heart or airway disease	Less reserve when panting

Do not wait for a “tough” breed to look distressed. They will often keep walking until they cannot.

First aid — then a vet, fast

Start cooling with tepid (not ice-cold) water. Never plunge a dog into an ice bath or pack them in ice. Sudden chilling can worsen shock.

Move to shade or an air-conditioned room
Pour cool water over the body, belly, inner thighs, paws and neck — not ice
Wet towels — replace them as they warm; do not wrap tightly and trap heat
Fan if you can
Small sips of water if they are conscious and can swallow
Phone the vet — keep cooling during the call
Out of hours: out-of-hours vets or the Vets Now finder

Even if they seem better, internal damage (gut, kidneys, brain, clotting) can still be underway. Always get a vet to assess after a true heatstroke episode. Do not “see how they are after a nap”.

If they collapse, have a seizure, or cannot stand, treat it as emergency vet care — cool on the way, do not delay the car journey to finish home first aid.

Cars

According to the BVA, car interiors reach dangerous temperatures within minutes. A “two-minute shop” is enough. Windows on a crack do not make it safe. If you see a dog in distress in a vehicle, call 999.

The same rule applies to caravans, conservatories and parked vans.

Prevention

Walk at dawn or dusk in warm weather
Five-second hand test on tarmac before you go
Shade and several water bowls
Never leave a dog in a car
Swap fetch for indoor sniffing games on heatwave days
Watch flat-faced breeds from the high teens °C, not only in “record” heat

Use the too-hot-to-walk checker before a planned outing. It is a sense-check against UK summer advice, not a thermometer for your dog.

What the vet may do

Expect an exam, temperature check, blood tests and often intravenous fluids. Some dogs need oxygen, anti-sickness drugs, or clotting support if heatstroke has triggered a cascade. “They cooled down in the car” does not cancel the visit — gut lining and kidneys can fail hours later.

Recovery at home, if the vet sends you home, usually means rest, small meals, watching for vomiting, diarrhoea, dark urine or wobbliness, and a booked recheck. If signs return, go back the same day.

Species other than dogs have their own summer risks — rabbits and flystrike, guinea pigs, birds, reptiles — on hot weather pet safety.

Sources & further reading

Facts in this guide are rewritten in plain English from publicly available UK advice. We name the organisation where a specific point comes from their guidance. Links below go to the original pages — use them to read the source material directly.

PETHEALTH+ is independent. These organisations do not sponsor, approve, or partner with this website. Guidance checked against sources listed below (last updated 2026-08-13).

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Frequently Asked Questions

What are the signs of heatstroke in dogs?: Heavy panting that does not settle, excessive drooling, bright red or very pale gums, vomiting, diarrhoea, wobbliness, collapse or seizures. It can develop within minutes in a hot car or after exercise in heat.
Should I use ice on an overheating dog?: No. Use cool (not ice-cold) water on the body, wet towels and fanning. Offer small drinks if they are conscious. Phone your vet while cooling. Ice baths can worsen shock.
Which dogs are most at risk?: Flat-faced breeds, overweight dogs, thick-coated breeds, puppies, elderly dogs, and those with heart or airway disease. Any dog can overheat in a hot car or after strenuous exercise in heat.
When is it too hot to walk a dog in the UK?: Many UK vets cut exercise for sensitive dogs from around 20°C and skip normal walks in the mid-20s. Always do the five-second pavement test. Use the PETHEALTH+ walk-temperature checker as a sense-check, then watch your dog.