Using the toy trains is easy. Just take Thomas, Percy, or Kana and place them in either warm or icy cold water. You'll see their colors change and hidden decorations appear. When done playing, dry the trains with a soft cloth. Keep the trains away from sharp objects to avoid scratches. Don't use harsh chemicals to clean them. These trains are suitable for kids 3 years and older, so make sure younger children don't put them in their mouths. Have fun creating exciting railway adventures!