My favourite cooling beverages include coconut water (the best thing for getting your electrolytes), freshly squeezed juice (or 100% pure juice diluted with some water), water with a bit of lemon/lime juice (also great for electrolytes), and iced herbal teas of all kinds (peppermint is especially refreshing). Fruit smoothies full of berries and a banana are also fantastic and very tasty.
Ice cream is sooo good, there's no way that I would avoid it completely. One of my favourite places on the beach is a little gelato shop run by an Italian family that definitely puts quality first :) Their gelato is delectable and possibly one of the best desserts I've ever had. It is a treat though, not something to eat all the time :) Unless you go on an ice cream diet :)
Since daily doses of ice cream may not be possible, some healthier alternatives include frozen bananas dipped in chopped nuts (and/or melted chocolate, yum!). This just reminds me of the frozen banana stand on 'Arrested Development' and makes it extra fun and enjoyable. An option in place of popsicles is to make your own using real fruit juice. Some people use ice cube trays that have fun shapes to make them extra entertaining for kids (I find them very entertaining also). Fruit can also be pureed, cut up into fun slices, and put on a stick to make it even more summery and exciting. I love fruit kabobs made with grapes, strawberries, and pineapple. Or apple. Or anything, I don't think there is any fruit that I do not like. This kabob may not be featuring seasonal eating, but it is a nice treat.
These are just a few ideas to experiment with. Once we decide to get inventing and make things ourselves the possibilities are literally endless!
Hope your summer is off to a tasty and beautiful start!