When you blow on your hands to warm them, you add kinetic energy to the air molecules, which in turn raise the temperature of the air near your hands. This increase in temperature causes the molecules to move faster and transfer energy to your hands, warming them up.
When you blow on a bowl of hot soup, you transfer the kinetic energy from your breath to the molecules of the soup, which cools down the soup by reducing its temperature. Since the molecules are moving slower than they would at a higher temperature, less energy is transferred to your hands as you touch it.