My dad is 68 and watches DD once a week. He's not in the best shape and has been having increasing back and sciatic pain over the past several weeks. He used to take her on a stroller walk in the afternoons to play in the park, but it's been really hot lately. I know he's getting kinda bored and just doesn't know what to do with her during the days. I've been trying to think of some play activities or ideas for them to do to keep them both occupied. Any ideas?

He doesn't have a carseat int he car, so any activities would have to be at home or at the nearby park.