With the help of an adult fill two bowls with water, one with really cold water and one with hot/warm water (not too hot to touch)!
Put your fingers into the bowls and notice the temperature of the different bowls of water.
Now add an ice cube into each bowl. Talk about what you think will happen? Will the ice-cube get smaller? Will it disappear altogether?
Have a look at the bowls every 2 minutes. Has anything changed? Talk about what is happening and take some photos if you can each time so you can see the changes. Put your fingers into the bowls again, has the temperature changed from the beginning of the experiement.