cold as ice

(adjective) very unfriendly

Example Sentences:

The new teacher was unpopular because she was cold as ice. She should be more friendly.

A: How is your new boss?
B: He’s as cold as ice. He was unfriendly to everyone!

Media:

Similar idioms:

1. give someone the cold shoulder
2. throw cold water on
3. on thin ice
4. cold feet
5. devil’s advocate