Heat is dangerous for cats as well as dogs. Here are some tips to help your cat cope with high summer temperatures and humidity:
Never leave your cat in a car without the a/c on for any length of time in warm weather. A car can get to over 120 degrees F inside in just a few minutes
Always have clean, fresh water available wherever the cat resides, esp. in hot weather. If your cat is not a big water drinker, feeding canned food at least once per day will help to increase water intake.
White cats and cats with white skin/hair around the eyes, ears, mouth and nose are prone to getting squamous cell carcinoma from sun exposure. Keeping your cat indoors can reduce the risk of cancer from sun exposure.
If your cat goes outdoors, make sure he/she has access to shaded areas.
Keep your cat indoors during the hottest part of the day (11:00am-3:00pm).
Avoid strenuous exercise or playing during hot times of the day.
If your house is hot and you are uncomfortable, your cat likely is too. Signs that your cat is over heated are panting, lying on their side with legs stretched out, flushed or pinker than normal tongue, nose and gums. If you are able, turn on a/c or get a fan going.
If you think your cat has heat stroke (has signs listed above plus has collapsed and non-responsive), this is a medical emergency. Go to an emergency veterinary clinic ASAP. Never immerse your cat in cold water in this situation, as this could make you cat worse. You can wrap the cat in a wet towel and apply some rubbing alcohol to their footpads.