How about taking a break at a hotel restaurant for Lunch near a Park for an Air conditioned break from the parks? Here are some suggestions for Lunch near each Park:
Magic Kingdom: The Wave (Contemporary Resort) , Kona Cafe (Polynesian), Trails End (Wilderness Lodge) and grand Floridian Cafe (Grand Floridian)
DHS/Epcot: Boardwalk Bakery (Between Beach Club and Yacht Club), Garden Grove Cafe (Swan) and ESPN Club (Boardwalk)
Animal Kingdom: Sanaa (Animal kingdom Lodge)
This gets you an air conditioned break without going to your care because your either walking distance (Contemporary and Boardwalk) or short Disney Transportation ride away.
If I may add to this and critique a little....
MK day, yes consider a break at the Contemporary, the Poly or the Grand Floridian (All accessible by Monorail from MK, as well as boat for Poly and GF). Trail's End is not at the Wilderness Lodge, it is at Fort Wilderness Campground. Since it is at the campground there is no cozy lobby to relax in like there are at other parks. There is a nice lobby at the Wilderness Lodge (accessible by boat from MK), the restaurant there is Whispering Canyon Cafe.
DHS- Captain's Grill at the Yacht club was the most relaxing lunch I have ever had at Walt Disney World. An the food was excellent. The Fountain at the Dolphin is great for Burgers and Ice Cream. (Both accessible by boat from DHS)
Epcot, truthfully, I wouldn't leave Epcot to eat. There are too many great restaurants there. There are also lots of places to relax.
In Future World- Inventions, the Land, the Living Seas, the test track exit.
In World Showcase- Movies in China, Canada, France. The American Adventure. Little Alcoves in Morroco, Japan, Mexico, China, England.
Animal Kingdom-
I personally never felt the need to leave AK. There are some nice places to eat right in the park. There are 2 Air Conditioned shows that are not to be missed. Between getting seated and the shows themselves, that is 2 hours sitting in air conditioning right there. Also has nice walking paths to see animals, and a relaxing train ride to see some more animals. Plenty of opportunities to relax.