What are the signs of heatstroke in dogs?

Heavy panting, excessive drooling, bright red gums, vomiting, diarrhoea, wobbliness, collapse, or seizures. It can develop within minutes in hot cars or after exercise in heat.

Should I use cold water on a overheating dog?

PDSA and RSPCA advise cool (not ice-cold) water on the body, wet towels, and fanning. Offer small amounts of water to drink. Phone your vet while cooling — heatstroke can be fatal without treatment.

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.

Dog Health

Dog Heatstroke UK — Signs, First Aid & Prevention

Published 1 June 2026Last updated 25 June 20262 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 continuing to cool. Do not ice-bath — sudden chilling can worsen shock. Prevention beats treatment: no hot cars, no midday walks.

How heatstroke happens

Dogs cool mainly by panting. When heat gain exceeds what panting can remove, core temperature rises dangerously. Common triggers in the UK:

Being left in a car
Midday walks on hot days
Overexertion (ball chasing, running)
No shade or water outdoors

First aid — then vet, fast

According to the PDSA and RSPCA, start cooling with tepid (not ice-cold) water — sudden chilling can worsen shock. Then:

Move to shade or air-conditioned space
Pour cool water over body, belly, paws, neck — not ice
Wet towels — replace as they warm up
Fan if available
Small sips of water if conscious
Phone vet — continue cooling during the call

Even if your dog seems better, internal damage may have occurred — always get vet assessment.

Prevention checklist

Walk at dawn/dusk in heatwaves
Five-second pavement test before walks
Shade and fresh water always available
Never leave in cars
Watch flat-faced breeds closely above ~20°C

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 2026-06-25).

Related guides

Frequently Asked Questions

What are the signs of heatstroke in dogs?: Heavy panting, excessive drooling, bright red gums, vomiting, diarrhoea, wobbliness, collapse, or seizures. It can develop within minutes in hot cars or after exercise in heat.
Should I use cold water on a overheating dog?: PDSA and RSPCA advise cool (not ice-cold) water on the body, wet towels, and fanning. Offer small amounts of water to drink. Phone your vet while cooling — heatstroke can be fatal without treatment.
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.