My greatest battle with my in laws are the AC settings. It's 40C (105F) outside with 75% humidity. They want the AC set to 25C (77F) and I want it set at 18C (65F). I'm currently in a suspended state where everything I do is 0.5x speed because it's too damn hot.
Discussion
Its not healthy to set it more than 7 degrees difference from outside
25 is too hot for you??
From my experience in India (commercial establishments like malls and office buildings always turn it way down), big indoor outdoor temperature difference would make me sick. But then people are built different, maybe it doesn't affect everyone the same.