How to pass the time with a 9 month old

Ann

Specifically between last nap and dinner. He gets in such a whiny, doesn't want to do anything mood during this time. I usually like to go run an errand, but I can't leave the house every day at this time. And it's so flippin hot outside (live in Texas) so can't go on a walk or play in the backyard. Every other activity around the house seems to lose its luster by now. Any new ideas??