I HATE cooking in the summer. Okay, I'm not much of a fan of cooking anytime of year, but especially when it's hot!
I make a lot of throw together meals where we just throw together whatever we can without cooking. Today for lunch we had chex mix, a cucumber and a pear. Not too bad health wise, no cooking and super easy. In the summer we eat a lot of sandwiches or even just crackers and cheese with fruit or cut up veggies, maybe some yogurt or cottage cheese. Think about what you might serve as just appetizers without cooking - fruit, veggies, cheese, crackers, tuna dip, tortilla roll-ups, etc. Put 2-3 of these together and you've got an easy, healthy, no cook meal.
I also do a lot of cooking once - eat 2-3 times. My favorite one is to grill a bunch of chicken breasts and serve with fettucine the first night. Next night is cut up chicken with cheese in tortillas. Next night is grilled chicken salad. Cooked once - 3 meals. My son won't eat a 'salad' but if I just give him some of the ingredients separately he will eat them.
My former DH would never eat like this but he was not home much for meals anyway so my DS and I have always just eaten quick simple throw together meals like this.