Crawling along on their tummy is not a normal thing for a dog to do. To teach them this trick, get them to lie down and stay. Get down to their level and offer them a treat by hand, just out of their reach. If they try to stand up, command them to lie down and stay again. When they try to wiggle forward on their tummy, praise and reward them. Then just repeat the whole thing till they get the idea. Soon you will just give the order and they will perform.
On a hot day, fill up a paddling pool with cool water, throw in a dozen or so tennis balls and let your dog loose to dive in and retrieve the balls. As they try to grab the ball, the ball will sink, so it is not as easy as it sounds. Not only will your dog cool off, but they will get exercise without having the worry of overheating in summer. Plus, it's a whole lot of fun.
The beach is a great place to take your dog. As long as the beach is dog-friendly, you can let your dog loose to play with the other dogs, run in the sand, or even let them splash in the shallow waves. You can let them dig to their heart's content, or just wander along the beach while your dog checks out every rock and shell. Tidal pools make ideal fishing spots for your dog. There is so much to do for a curious Silkshire Terrier!