Many dogs like to be outdoors during the summer, but too much heat and humidity can cause them stress. Signs of heat stress can include excessive panting, difficulty breathing, increased heart rate, drooling, depression, bloody vomiting and diarrhea, collapse, and seizures. At temperatures over 85ºF, dogs may show signs of overheating. The humidity level is also a factor. A warm, humid day with full sunshine may cause more problems than a hotter day with a nice breeze and some cloud cover. Heat stress is a medical emergency and warrants a rapid response and visit to the veterinarian. However, with proper care and a few husbandry techniques, you can ensure that your dog will be cool and comfortable during the hot, long summer.
Providing Plenty of Cool Water
Water is the single most important thing to give your dog during hot summer days. Your dog should have access to cool, clean drinking water at all times. In the summer, water can evaporate quickly, so check on your dog and the amount of water in its bowl several times 
throughout the day. Provide water in a larger bowl or make sure the bowl is filled at all times on really hot days. It is also possible to put an attachment on an outdoor faucet that allows dogs to lick and get as much water as needed. This will give the dog constant access to cool water while outside.
Misting your dog or providing a shallow pool will also help keep your dog cool. Use a handheld spray bottle to mist your dog. Some dogs do not like misting, so be sure you are not scaring your dog if you use this method to keep it cool, and discontinue the misting if it stresses your dog. Home improvement stores sell misters that attach to garden hoses. Such a mister and can be be set up in a corner of the yard so that the dog can use it when needed, and the mister will lower the surrounding air temperature.
Another alternative is a shallow pool for your dog to lie or sit in. Make sure the pool is shallow enough for the dog to touch the bottom because not all dogs can swim. Small children’s wading pools are great for this purpose. Replace the water daily to keep it clean and cool. Do not leave a dog unattended in a pool or other body of water where it cannot touch the bottom or it could drown. In order for a dog to cool down, its skin needs to become cool, not just its coat. For short coated breeds a wet towel can be put on the back of the dog to cool it. If you use water to cool your double coated breed of dog, you will need to be careful to dry the dog thoroughly to prevent hot spots or other skin problems that can develop in warm, wet environments.
Placement of an Outdoor Dog Kennel
Owners who keep their dogs outside need to take special precautions during the different seasons of the year. In the summer, the placement of the dog kennel is critical to keeping your dog cool. Make sure that the location you choose is shaded during the hottest times of the day and that it has adequate airflow. Lack of airflow during the summer can cause heat stress, even if the animal is in the shade—for example, as when a kennel is in a garage. Although the interior of a garage is shaded, the three walls of the garage prevent adequate air movement. (In addition, keeping a dog in a garage is not a good practice because of vehicle exhaust fumes and other hazardous elements.) Placing the dog in a spot that gets plenty of wind and natural airflow is best for the health of the animal. There are many commercial sun screens available that can be put over the top of a dog run or strung between posts and a fence. These sunscreens either filter or reflect the sun, keeping the kennel area much cooler.
Housing Your Dog Inside
Owners who keep dogs inside and exposed to continuous air conditioning need not take extra steps to keep the animals cool. On the other hand, if you keep your dog outside in the heat but want to bring it into the cool environment of the house, you must be careful. Some dogs may become stressed when they are inside the house because they are not familiar with the new surroundings. If this is the case, it would be better to keep your dog outside, but to make sure it has an adequate water supply and shade to keep it cool. You may consider bringing an outside dog in during the hottest times of the day. You could keep it confined in a single room if it is not normally inside.
If your house is not air conditioned, fans can be helpful. Battery operated fans that hang from the front of dog crates can provide additional airflow. You might find your dog seeks out cool tile or linoleum to sleep on rather than a carpet or dog bed.
Walking Your Dog
Avoid walking your dog during the heat of the day. If you are going to exercise your dog, make sure you do it in the morning or in the evening when it is cooler out. This will help the dog stay cool and not become overheated and stressed from the temperature. Be careful of hot pavement, which can burn the dog’s paws. A good rule of thumb is, if you would not walk on a surface barefoot, you should not ask your dog to do so. Black pavement can be particularly dangerous and can cause burns. After exercising your dog, make sure there is ample water so the dog can rehydrate. Older animals may not be able to handle the heat as well as younger animals, so watch your older dog carefully when exercising.
Grooming
To help your dog withstand the hot weather, trimming the coat will make it easier for the dog to remain cool in the summer. If your dog has closely trimmed fur, make sure 
the dog does not get sunburned. Light or pale skinned dogs have a greater chance of becoming sunburned, which is painful and dangerous. To help your dog withstand hot temperatures without trimming, be sure to regularly groom the dog to remove loose hair. Shaving dogs to the skin is not recommended because it can lead to post clipping alopecia, a condition in which the coat does not grow back to its original length and may change in texture. This is especially common in plush and double coated breeds such as Chows, Samoyeds, and Pomeranians. A regular brushout, bath, and complete blow dry will do much to keep your dog comfortable in hot weather.
Loud Noises
During the summer, loud noises can become a problem for dogs. These noises can be anything from thunder to fireworks. A dog will show signs of anxiety by pacing or trembling. To help offset your dog’s fear and to help them become less stressed, play with your dog to help get its mind off the stressor. There are also prescription drugs that your vet can be recommend to help decrease anxiety. Before using these drugs, make sure you consult with your veterinarian to make sure they are appropriate for your dog.
Traveling with Your Dog
Dog owners may travel a lot with their dogs in the summer. If you do travel with your dog, never leave it in your vehicle alone. The vehicle’s internal temperature can rise quickly, increasing your dog’s chance of heatstroke. Not only could your dog get heatstroke, it might also become anxious. If you do need to stop, make sure someone remains in the vehicle with the dog. If that’s not possible, leave the dog at home. While the dog is traveling, if it is in a crate, there are numerous small battery operated crate fans you can attach to the door of the crate to provide air circulation. You may also find frozen ice packs or special chilling mats made to help dogs keep cool that can make the trip more comfortable.
Following the guidance provided in this article will help ensure that your dog has a safe and comfortable summer.
Jared Mracek and Lisa Karr-Lilienthal, Ph.D. – University of Nebraska–Lincoln