Complex sentence: If too much water is used at once, the steam will be cool with a clammy feel; a small amount of water on sufficiently hot rocks will evaporate quickly, producing a quickly dispersed steam consisting of small vapour particles.
Split into simpler sentences: If too much water is used at once, the steam will be cool with a clammy feel. A small amount of water on sufficiently hot rocks will evaporate quickly, producing a steam consisting of small vapour particles.