Awe,
I love this topic! One of the now lost fav places to rest in hot weather was the exit area in Universe of Energy. Seriously, had padded bench seats in AC with dim lighting. It was the best!
If you’re traveling with small children, I highly recommend the comfort stations for kids in each park. I remember the one in the Odyssey at Epcot as great to relax in w a kid.
To just relax in AC - for 1/2 hr to hr, I agree with finding Counter Service restaurants at off times. Back rooms in Pecos Bills are often quiet, the second floor at Harbor House - also has a great bathroom.
Also, in MK - Carousel of Progress, Country Bears, PhilharMagic, Hall of Presidents can all be great places to sit in the dark in AC and nap - Hall of Pres is my fav.
In Epcot, there are great places in many of the countries to stop and rest, some inside and some outside. Canada, England, France, Morocco, Japan, China, Mexico all come to mind. In Mexico there’s the water ride that usually doesn’t have a wait. There used to be seating inside. In France and China, the movies are also a great places to rest and relax in AC.
Animal Kingdom is tougher, if not the toughest to find places inside. The QS restaurants would be the best. I’m going to head to the Nomad Lounge in AK as well.
HS has some shows to sit down at. One Man and his Dream, Indiana Jones though that’s not AC. The Lounge connected to the Brown Derby.
I’m looking at places to draw and sketch during this trip and take some quiet moments.
Hope you can find some relaxing places!