Heatstroke kills dogs — and it is almost entirely preventable. Dogs cool themselves mainly by panting, which fails fast in heat and humidity, so a hot car or an overdone summer walk can become an emergency in minutes. This guide covers the warning signs, the right way to cool an overheating dog, and how to keep walks safe in warm weather. Never leave a dog in a parked car, even briefly with the windows cracked.
Warning signs of heatstroke
Early heatstroke looks like a dog working hard to cool down: heavy, frantic panting, excessive drooling, and bright red or dark gums and tongue. As it worsens you may see weakness, stumbling, glazed eyes, vomiting or diarrhoea (sometimes with blood), and finally collapse, seizures or unconsciousness. A normal canine temperature is about 101–102.5°F (38.3–39.2°C); heatstroke is generally over 104°F (40°C) and above 106°F (41°C) is critical. Do not wait to confirm with a thermometer if a dog is clearly struggling — start cooling and get help.
How to cool an overheating dog
- Move to shade or air-conGet the dog out of the heat immediately and stop all activity.
- Use cool, not ice-cold, waterPour or sponge cool water over the body — especially the belly, groin, armpits and paws. Ice-cold water can constrict vessels and slow cooling.
- Add airflowA breeze or fan over the wet coat speeds evaporation and cooling.
- Offer small sipsLet the dog drink cool water if it wants, but do not force it.
- Go to the vetCool on the way. Stop active cooling once the dog is around 103°F to avoid over-cooling, but still have the vet check it.
Never leave a dog in a car
On a warm day a parked car becomes an oven within minutes — even at a mild 70°F (21°C) outside, the interior can climb well past 100°F (38°C) quickly, and cracking the windows barely helps. Dogs have died in cars in under fifteen minutes. The rule is simple: if you cannot take the dog with you, leave it at home. If you see a distressed dog locked in a hot car, call local authorities or emergency services.
Safe walks in hot weather
Walk in the cool of the early morning and evening, never the midday peak. Test the pavement with the back of your hand for seven seconds — if it is too hot for your hand, it will burn paw pads. Carry water, take frequent shade breaks, and keep walks short and slow on hot days. Plan distance with our walk distance calculator and adjust intake using the water intake calculator. On very hot days, swap the walk for indoor games or scent work.
Dogs at highest risk
Some dogs overheat far more easily: flat-faced (brachycephalic) breeds like Bulldogs, Pugs and French Bulldogs, whose airways make panting inefficient; overweight dogs; very young, old or unwell dogs; thick-coated and dark-coated breeds; and any dog exercising hard in heat. These dogs need extra caution, more shade and shorter activity. Acclimatise gradually as the weather warms, and know your individual dog’s limits.
Frequently Asked Questions
What are the first signs of heatstroke in a dog?
Heavy, frantic panting, heavy drooling, and bright red or dark gums are early signs. As it worsens you may see weakness, stumbling, vomiting, diarrhoea and finally collapse or seizures. Any dog struggling in the heat needs immediate cooling and a vet.
How do I cool down an overheating dog?
Move it to shade or air-conditioning, stop all activity, and pour or sponge cool (not ice-cold) water over the body, especially the belly, groin and paws, with a breeze or fan for airflow. Offer small sips of water and get to a vet, cooling on the way.
How hot is too hot to walk a dog?
Walk in the cool of early morning and evening and avoid midday heat. Test the pavement with the back of your hand for seven seconds; if it is too hot for you, it will burn paw pads. On very hot or humid days, skip the walk and play indoors instead.
Can a dog die from being left in a car?
Yes, and quickly. Even at 70°F outside, a parked car can exceed 100°F within minutes, and cracking the windows barely helps. Dogs have died in under fifteen minutes. Never leave a dog in a parked car — if you cannot bring it with you, leave it at home.
Sources
- American Veterinary Medical Association (AVMA) — heatstroke and pets in vehicles guidance
- American Kennel Club (AKC) — heatstroke in dogs and hot-weather safety
- ASPCA — hot weather pet safety tips
Last updated 25 June 2026.
