When she says this, while climbing over me to take her very loud phone conversation outside, I'll build the "wall" (designed to keep her from breathing on me) extra high. I'll use 3 pillows, so it's like the great tower of China between our heads.
I'll fall asleep. When I wake up in the morning, I'll be secretly happy that I sleep-yelled about the A/C. I'll be happy she spent several minutes in the middle of the night wondering why I was ranting about the A/C—and why it kept turning on and off.
And when she exclaims/asks: "Why did you stack the pillows so high?!"— I'll start laughing really hard.
Gosh. I love her so much.