Nowadays, Norm, the heat is different.
I lived in FL with my ex from 1969-71 without AC. It would be cooler at sunrise. There were more wooded areas, and lots more shade. No later than 2 pm we'de have our 20-30 minute thunderstorm, and then the temps would've decreased to the 70s-80s. At night the wind shifted and was cooler. Remember each large tree cab show a 10*F decrease in temperature in its shade.
Now most of the wooded areas have been pushed down and concrete substituted. It soaks up heat all day and then radiates it back all night. The thunderstorms are patchier and start at all different hours of the day. In the olden days we would have our 25 -20*F difference between night and day. That is now reduced in the summer to 8-11*F difference. If you have a 96*F day an 86*F low isn't going to feel much better.
I have been diagnosed with asthma, at age 57 (in my defense, it was atypical) and one of the triggers is heat.
I lived without a/c in 2004 when Sebring was hit by Charlie, Frances, and Jeanne and we would wait for electricity to be restored and 3-4 days later another hurricane would take out all the restored lines. I only survived by re-instituting the siesta and spending late afternoons and evenings in the lake. Went through D batteries (for the fans) like crazy. Bucketed water from the lake to the house for toilet flushing and ate uncooked snacky foods all summer.
I used to turn on my a/c on Memorial Day and turn it off Labor Day when kids were small. Gradually A/C has started earlier and run later each year. Heat correlates with th return of the swallow tailed kites each summer. They used to return in May/June. I spotted my first one this year in the first week of March. They stay later in the autumn too. I think it was 2013 (or 2014) ? first time I ran my a/c all year.
I like cool/cold weather. I was running around the Len Foote Hike Inn in the mountains of GA (Amicola SP) late November a few years back in shorts and a t shirt while everyone else was bundling up in fleece- BUT used that old swimmers trick to avoid hypothermia- a light
layer of petroleum jelly everywhere I could reach. Works wonderfully to hold the warm in/keep cold out.
Can hardly wait for 2017 and my projected trip to Canada! I HATE this heat and humidity!