Spock and McCoy in “Unfinished Business”

Spock

I have a question for the doctor. [Kirk leaves] Doctor, the ship's temperature is increasingly uncomfortable for me. I've adjusted the environment in my quarters to one hundred twenty five degrees, which is at least tolerable. However, I -

McCoy

Well, I see I'm not going to be making any house calls on you!

Spock

I wondered if perhaps there was something which could lower my sensitivity to cold.

McCoy

I'm not a magician, Spock - just an old country doctor.

Spock

Yes...as I always suspected.