When someone is given the cold shoulder, they are deliberately ignored or shunned. When someone is warm with someone, they are kind, gentle and welcoming towards them. Conversely, when someone is cold, they take no notice of someone and disregard them at every turn. This idiom is commonly heard in both social and professional situations.
The man seemed anxious because his wife had been giving him the cold shoulder all day.
I’m dreading the meeting with my manager later, as he’s been giving me the cold shoulder all afternoon.