It's so hot in our corner of France at the moment we are constantly trying to think of ways to keep the kids cool (other than let them run round all day with no clothes on!) Pinterest is a great source for finding things to do with kids (check out my 'for the boys' board) and this is where I got this idea from.
Find a container and lots of little objects to put inside. Fill the container with water and leave in the freezer. When it's completely frozen release the ice block and give to your child with something they can use to chip away at the ice. Simple summertime fun! Watch your child have fun as they try and break the ice and release the objects embedded inside.
The only problem we had was that with it being so hot the ice started to melt rather quicker than hoped. Reuben also decided that the best way to break the ice was to smash it to the ground with great force. Boys!