The exact temperature tolerance may vary from cat to cat, depending on their lifestyle and other factors. Humidity may also contribute to overheating.  Older, overweight, or short-nosed (Persians, for example) kitties are much less heat tolerant than other cats, and therefore can overheat more quickly. The same is true for cats with certain medical conditions.  When they start to get too warm, pets may first experience heat exhaustion, which is when they slow down or become lethargic in an attempt to reduce their body temperature.

These symptoms might also be the early stages of heatstroke — a serious condition that can cause organ damage or death. Symptoms of heatstroke can include glazed eyes, lethargy, difficulty breathing, a rapid heart rate, wobbly walking, loss of balance, vomiting, seizures, red gums or tongue, and collapse.

Unlike dogs, in cats, panting is not considered normal. This can also be a sign of overheating — your cat is too hot.

How To Keep Your Cat from Overheating

Keep your cat indoors. Vets commonly recommend an indoor lifestyle for many good reasons. In addition to avoiding temperature extremes, staying indoors virtually eliminates the risk of being hit by a car, getting lost, getting into fights with other cats or wildlife, and exposure to certain infectious diseases like FIV.

  • Keep the temperature comfortable indoors. Use air conditioning if at all possible, or at least provide a fan and access to cooler surfaces like tile or concrete. You may find your cat stretched out for a nap on these surfaces, to help beat the heat. If the windows are open for a breeze, make sure there is a secure screen in place, so your cat can’t fall out of the window while exploring.
  • If your cat must go outside, take precautions. Make sure they have access to shade (somewhere with airflow, since enclosed structures can get extremely hot). Provide a grassy area, if possible, since hot pavement can burn paw pads. Keep fresh, cool drinking water available at all times. Avoid letting your cat out during the hottest hours of the day. And double check places like sheds before you close the door, to ensure your cat doesn’t get locked inside. To let your cat enjoy the outdoors without roaming too far, consider building a catio, an enclosed playpen attached to the home so your cat can come back inside at will.
  • Avoid dehydration. Cats drink water to help cool themselves, so fresh water should be available all the time. Even indoor cats may drink more in the summertime. Consider adding a cat water fountain to entice your cat to drink more, and watch for signs of dehydration (lethargy, dry or pale gums, and the skin between the shoulders being slow to sink back into place if you pull up on it).
  • Never leave your cat in the car on a warm day, not even for a few minutes. Temperatures inside a car can rise rapidly, even if the windows are cracked. Even on a cool day (the mid-60s), the temperature in a closed car rises to 130 degrees Fahrenheit in minutes. Brush your cat more often in the summer to remove their undercoat. A full shaving isn’t necessary, unless that’s their usual hairstyle, since cutting the hair too short may remove some of their natural sun protection.
  • Have a backup plan. Sometimes, power outages happen in the summertime, especially if you live in an area that also experiences summer storms. During these times, the air conditioning won’t work, and the temperature inside the home can rise rapidly. Consider having frozen water bottles on hand (put a towel over them) or use a cool, wet towel on your cat’s fur and offer them a fan. A cooling mat for pets can also be a good option. Sometimes, this still isn’t enough, so plan ahead for where you could take your cat if the power is out for an extended time.