Hot summer weather can be more dangerous to dogs than many pet owners realize. When a dog's internal temperature is raised too high (generally about 106 degrees F), a chemical reaction occurs that actually breaks down the cells in your pet's body and can result in death. But, thankfully, there are some simple common-sense steps you can take to keep your dog healthy and prevent heat stroke.

[edit] Steps

Ensure that any dog kept outdoors has plenty of water and shade. If the weather is unusually hot, take time to check the outdoor temperature in your pet's area. It may be too hot in some locations to leave your pet outdoors regardless of how much water and shade your pet has.
Restrict outdoor exercise to the early morning and late evening when temperatures are cooler.
Carry water with you when walking your dog. Watch your pet carefully for indications that he is over-heating, such as heavy panting, loss of energy, and any obvious weakness or stumbling. If your pet begins to show signs of heat suffering, stop in a shady spot and give him some water. If symptoms don't subside, take him directly home and seek veterinary care.
Never, never, never leave your pet unattended in a parked car. Even if you park in the shade and leave the windows open slightly, the internal temperature of your car can heat up and put your dog in fatal danger within just a few minutes.
Equip your car with window shades if you are planning a long car trip with your dog. Bring water and/or ice cubes along to help keep your dog hydrated and cool.

[edit] Tips

You can purchase cool pads for use in the dog's crate or in your car. When soaked with cool water, they keep the temperature down. Bandanas can also be used in this way.
Pharmacies carry athlete-grade ice packs that can be frozen and create little mess. Additionally, they can be applied directly to specific areas.
To help your dogs feel cooler, fill a spray bottle with water and squirt him.
Heat exhaustion is very common in bulldogs. Keep the bulldog inside as much as they need in order for them to cool down.

[edit] Warnings

If your dog is showing signs of heat stroke, use a rectal thermometer to check his temperature. If it is approaching 105 degrees, put your dog in a cool bath (or at least sponge him down) and call your veterinarian immediately. When your pet's temperature drops to 103 or 104 degrees, you can take him out of the cool bath so his temperature won't drop too quickly.
If your dog isn't taken care of properly (i.e. if he is left alone in the car), people around the area may report to the police. Be careful and always look out for your pet's safety.