1. To break the ice – when you lighten the atmosphere, especially during a first meeting.
2. The tip of the iceberg – a small, visible part of a larger situation.
3. To be skating on thin ice – doing something risky with serious or unpleasant possible consequences.
4. Put something on ice – put something – an idea or a plan – on hold.
5. The icing on the cake – an additional, positive thing to make an already good situation even better.
6. An ice queen – a woman with a cold, unfriendly manner.
7. To de-ice – to remove ice, especially from a car window with special liquid, but also the removal of excess ice from a freezer.
Polski 
English (UK)