Welcome to YorkieTalk.
I agree with Brit and Crystal. If your dog does need to lost weight, change the food he is eating. He will likely be more satisfied while losing weight easily. I would also hold the rice and pasta. Give chicken and salmon only in tiny amounts. My 8-pounder is satisfied with half a teaspoon of fresh food treats. When I give more, I compensate by reducing kibble.
Indoor fetch is a good substitute when walking and running outside is prohibited by high temps. During the summer, I have to get my boys out the door early in the morning and wait until late evening for the pavement to cool for walks.