thanks to you and everyone for the explanation - I haven't lived in the U.S for 20+ years now so I forgot all about air conditioning.

One of the things I do during the year is set the AC according to the outside temperature. During the winter months, my house is set to 70 degrees. As the average outside temperature rises, I increase it by 2 degrees for every 10 from 60. So when it's 100 degrees outside, it's 78 indoors. I have an older unit and watched in horror last year as it struggled and failed to cope with 110 degree temperatures.... I basically just gave up, shut it down, and waited until night time to turn it back on.