Carrie, I'm praying for cooler temps soon!
As Leni said, the tzatziki is great with chicken (or lamb), as a salad dressing, or a dip for pita and veggies. One thing I do in this kind of weather is grill something I can use again with leftovers. We just grilled London Broil (top round) the other night and had it the next night in a Caesar salad. Those rotisserie chickens from Sam's (and elsewhere) are great on their own and as leftovers...such as in pita bread with tzatziki, red onion and tomatoes.
I think I posted a recipe here for some meatballs from Weber that are so easy and good with the tzatziki. You can also slice them up to serve in sandwiches for another meal. I'll see if I can find the recipe.
Carrie, I found the meatball recipe and will bump it up.