(Have you) been keeping cool?
A question about one's wellbeing in hot weather. A: "How have you been during this brutal heat wave? Been keeping cool?" B: "Oh yeah, thanks to the air conditioning in the office."
keep cool
1. To stay calm. In this usage, a possessive pronoun is often used between "keep" and "cool." You know they're going to try to antagonize you during the debate, so just keep cool. I always try to keep my cool when dealing with the cable company.
2. Literally, to not get overly hot, as in hot weather. A: "How have you been during this brutal heat wave?" B: "Oh, keeping cool, thanks to the air conditioning in the office."