We humans can handle a heat wave with only a few minor adjustments: Extra fluids, limited activities, fans, and air conditioners. But animals don’t have it quite so easy: Cats and dogs will find ways to negotiate the heat, but it’s our responsibility to make the summer months more comfortable for them.
If you leave a pet alone in the house on a summer day, the interior will heat up as the temperature climbs. The easiest solution is to leave an air conditioner running. (It doesn’t need to be set for a low temperature -- about 85 degrees Fahrenheit is sufficient.) If you don’t have an air conditioner, use fans, and provide your pets with rug-free spaces. Remember to keep an ample supply of drinking water available at all times. Under no circumstances should you leave a pet in a car on a hot day.
For rabbits, ferrets, and guinea pigs, freeze plastic bottles filled with water, and put them in their cages. To cool the water in a fish tank, place a resealable plastic bag filled with ice into the water. (Never put the ice cubes in directly, because any contaminants in the ice will pollute the fish's water.)