Heat stress is a danger to your dog when the weather suddenly becomes hot or humid. Dogs do not sweat except for their paw pads. They need to exhale extra heat as they breathe. Panting is an attempt to blow out more hot air, but if the air they breathe in is extra hot, they cannot cool off. Older animals often have stiffer lung tissue, rib muscles and back mobility, reducing their lung capacity and ability to take better cooling breaths. We pay special attention to rib compliance in our dog patients. It is important not to shave a dense coat down during extreme weather, as a thick coat helps insulate against the heat. Trimming feathers (leg hair) and the belly is more appropriate. When the weather is milder, then you can consider shaving to about an inch long; any shorter and your dog is prone to sunburn.
Using water activity to help keep your dog cool is a fun way to stave off overheating, as water wicks heat away from the body through the underbelly and legs. This allows your dog to rely less on panting to exhale heat. Even just wetting the underside and legs of your animal will help it keep cool. You can lay down a damp towel on their bed or the bare floor to help with evaporative cooling. There are specific gel cooling beds or mats (Canine Cooler Gel Bed, Body Glove Dog Cooling Mat) that act as heat sinks to help dissipate heat away from your pet's body. These gel mats only work in shaded spots, not in direct sun. And please remember to never leave your pet in a sunny car, as even 5 minutes in a hot vehicle can have devastating effects.
Be aware that the ground heats up quickly under the summer sun. This can burn dog feet, and certainly make walking difficult if you have tender toes. So early morning and late evening walks are best. You can wet your dog's ear flaps, belly, feet and legs to allow them to stay cooler during the walk, or use the Swamp Cooler vest made by Ruffwear to help reflect heat while providing a cool gel layer over the trunk. Make sure your dog has plenty of shade if kept outside. Also, be sure plenty of fresh water is available at all times. Panting makes a hot dog even thirstier.