Heatstroke in Cats: Signs, First Aid and Prevention in Hot Weather

By Tailwisp Editorial TeamUpdated October 20, 20264 min read

Cats handle heat better than many pets, but they are not immune. A cat shut in a hot room, a parked car or a carrier in the sun can overheat in minutes. Heatstroke is an emergency, and quick action can make the difference between life and death.

What is heatstroke?

A cat's normal temperature is about 100.5 to 102.5°F (38 to 39.2°C). Cats cool down by resting, seeking shade, grooming and panting, but panting is far less efficient than sweating. If the surroundings are too hot, or the cat is stuck without escape, its temperature climbs. Above about 104°F (40°C) it is in trouble, and above 106°F (41°C), organs begin to fail. Heatstroke can lead to brain swelling, kidney failure, clotting problems and death.

Causes

• A parked car, even with windows cracked.
• A hot room, attic or garage with no ventilation.
• A carrier left in the sun. See how to choose a cat carrier.
• Being trapped in a dryer, a crate or a closet.
• Heat waves without cooling.
• Over-exertion in hot weather.
• Poor airflow, and a lack of water.

Higher-risk cats

• Flat-faced breeds, such as Persians and Exotic Shorthairs, which have breathing difficulties. See persian cat breed profile.
• Kittens and seniors.
• Overweight cats.
• Cats with heart or lung disease. See feline asthma.
• Longhaired cats, if not groomed.
• Dark-coated cats in direct sun.

Signs

• Panting, or open-mouth breathing.
• Drooling.
• Red or pale gums.
• Rapid heartbeat.
• Restlessness, or seeking cool surfaces.
• Vomiting or diarrhea.
• Weakness, stumbling or lack of coordination.
• Hot to the touch.
• Collapse, seizures or coma.

See cat emergency warning signs.

First aid

1. Move the cat to a cool, shaded, ventilated place, immediately.
2. Call your vet, or an emergency clinic, on the way.
3. Cool gradually. Apply cool, not ice-cold, water to the fur, especially the belly, armpits and paws, and put the cat in front of a fan. Wet towels laid on the cat can help, but replace them as they warm.
4. Offer small sips of cool water if the cat is alert, but do not force it.
5. Do not use ice or ice-cold water, which can cause blood vessels to constrict and trap heat.
6. Stop cooling when the temperature reaches about 103°F (39.4°C), to avoid overcooling, if you can measure it. See how to check your cat's vital signs.
7. Go to the vet, even if the cat appears to recover.

Veterinary treatment

Treatment may include intravenous fluids, controlled cooling, oxygen, monitoring of blood pressure and organ function, and medications. Cats are kept under observation for a day or more, since complications can appear later.

Prevention

• Never leave a cat in a parked car.
• Provide shade, ventilation and fresh water, in several places. See cat water fountains: worth it.
• Keep indoor temperatures comfortable, and use fans or air conditioning.
• Provide cool tiles, cooling mats and shaded spots.
• Groom longhaired cats. See grooming longhaired cats.
• Keep cats inside on very hot days.
• Check the garage, attic and shed before closing.
• Travel with air conditioning, and never leave a carrier in the sun. See how to travel with a cat by car.

See keeping cats cool in hot weather and summer safety for cats.

Heat exhaustion versus heatstroke

Heat exhaustion is the earlier stage, with panting, restlessness, drooling and seeking cool places. At this stage, moving the cat to a cool place and giving water may be enough. But it can turn into heatstroke quickly, and you cannot always tell the difference at home. If you are unsure, treat it as heatstroke and call a vet.

After the emergency

Even cats that seem to recover can develop kidney failure, clotting problems or neurological signs in the days that follow. Follow your vet's advice on rechecks and bloodwork. Keep your cat cool and calm for several days. Heat sensitivity may persist, so be extra careful in hot weather.

Cooling mats, fans and hydration

Many cats enjoy a cooling mat, a tile floor, or a shaded spot by a window with a fan. Give several water bowls, and consider a fountain. Wet food adds moisture. Keep blinds closed in the day, and ensure there is somewhere cool to retreat. See how to get a cat to drink more water.

Cats stuck in hot spaces

Cats can be trapped in garages, sheds, cars, dryers or boxes. If your cat goes missing in hot weather, check these places first. See how to find a lost cat.

When to see a vet

See a vet immediately if your cat shows any signs of heatstroke. Use the US vet directory to find a clinic.

This article is general educational information, not veterinary advice. Every cat is different. If your cat is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.