When your dog first starts his fitness program, his paws are likely to be tender. It takes time and many miles of walking and running to build up firm calluses. Even then, the hard, hot pavement of a city street may be more than his feet can take. Long walks or runs are best kept to the grassy areas of parks. You may have noticed dogs don't perspire like people do.
Dogs lose excess body heat through the pads of their feet and from panting.
This process can be greatly aided by giving plenty of water both before and after heavy exercise. It's recommended, however, that you let your dog cool down after a long run before letting him slake his thirst. Otherwise, he may regurgitate the water, resulting in a hot dog who not only needs water but now also has an upset stomach. Don't assume that your dog will be able to exercise in every kind of weather condition. Be considerate, especially of extremes in temperature.