On a hot day, something nice is ice messy play for kids. The mess easily wipes up and the ice feels cool and inviting. Any size container, from a plastic sink to a kiddie pool. And almost any size ice. 
With several days of warm, sunny weather in the forecast, we had time to prep for this and freeze some containers of water overnight. We used 3 different plastic food containers so we could have a small, medium, and big. In the hot afternoon, we took the 3 containers and a large bin outside to the deck. Just in case it was hard to slide the ice out we also had a small container of warm water. This wasn’t needed tho because the ice slid out almost right away. While I went back to the kitchen for some tools and toys to dig in the ice, the kids were feeling the ice, picking it up, and sliding it around.
To add to the fun, they also used a big eyedropper, baster, spoons, and a toy teapot. They scooped the water from the small container and squirted it over the big chunks of ice. The outside began to melt quickly, leaving a frozen core in the middle. It took 10 minutes for the small chunk of ice to melt to the size of a hockey puck, and much longer for the medium and big chunks. Both kids continued playing and even though the water was cold, there was no complaining. Of course, the splashes on clothes felt refreshing.
While plain ice is nice, you might want to freeze something small in the ice for kids to dig out. Some possibilities are small plastic animals or people. We’ve done this with dinosaurs and pieces of Lego. Once the kids got the Lego, then they could build with the bricks. Buttons, bottle lids, and flat glass marbles can be pirate treasure to dig out of the ice instead of sand.
Playing with ice is both a form of messy and sensory play. Kids are busy discovering what works for making ice melt and what doesn’t. They are using language and developing thinking skills like observing, judging, comparing, predicting, and focussing attention. They are also achieving a goal when they finally get objects out of the ice or make it all melt. Is it hot enough for some ice messy play in your area?