Build with Ice Blocks! Mix paint or food coloring with water and pour it into cardboard milk cartons, then put them in the freezer overnight to make colorful ice blocks. You can also make smaller blocks by freezing colored water in plastic food containers or ice cube trays. When they're ready show your child how to build by sticking blocks together with water. They won't last long in the summer heat but it's a fun way to construct and stay cool!