Usage patterns
〈人〉に冷淡だto be cold/indifferent toward someone
He was cold toward the new employee.
〈人〉を冷淡に扱うto treat someone coldly
I was angry at the clerk who treated customers coldly.
冷淡な態度をとるto take a cold, detached attitude
She took a cool, detached attitude toward that topic.
冷淡にあしらうto give someone the cold shoulder; to brush someone off coldly
I made a request, but I was coldly brushed off.