It's 88 degrees in my house right now.
I wear tank tops, shorts and have a fan or two going. Fans in the windows at night to bring cooler night air in.
I do open and close certain windows to try let cooler night air in and keep warmer air out... but in this old farmhouse with little shade and a black roof... it honestly doesn't make much difference.
(In the winter the thermostat is set at 63 degrees and the furnance sometimes runs non-stop. )
The other thing that really helps me with the temps is that I go outside and pull weeds, take care of the chickens and dog and just soak up some rays. Stand in the sun on a 90+ degree day and then come in, take a shower and sit in front of a fan. It feels pretty good. Go all summer without A/C and you'll have a new found appreciation of a light breeze, a shade tree and a cool drink.
Being warm in the house actually makes it much easier to go outside and take care of the stuff outside.
I used to think I die without A/C... in reality, I very much like not running it. It hasn't affected my allergies or asthma, in fact, I feel better without it. I do need to wash clothes more often and use a bit more water.... but I'm saving hundreds of dollars by not using it.
What cracks me up about how some people set their thermostats is that they'll have them set real high in the winter but then turn them way down in the summer. Like 78 degrees is ideal in the winter but far too hot in the summer. That makes no sense at all.