Hello Deborah and thanks for asking the Disney Parks Moms Panel such an important question about your families trip to the magic of Walt Disney World Resort.
As the parent myself of a teenager who suffers with Chronic Fatigue Syndrome (M.E) I can completely relate to the concerns you have for your dear son's health and wellbeing during your upcoming Disney vacation. My teen also finds it tricky to walk and stand for long periods of time and this can be exacerbated by the heat & humidity of the Florida climate plus the extra mental stimulation of enjoying a trip to her favourite destination!
So I'm happy to share that in my own past experiences of trying to limit my child's CFS symptoms we do try and incorporate rests into our Disney day by either returning to our Disney Resort Hotel for a mid-afternoon nap or by making a lunch time Advanced Dining Reservation as a scheduled sit-down break or by simply stopping by and enjoying the air-conditioned comfort of one of
Baby Care Centers which each Disney Theme Park benefits from.
Additionally now your dear son is older you may wish to consider
Wheelchair Rentals as a viable option and I'd like to also suggest the
Disney Parks Disability Access Service Card which can be useful for Guests who find it difficult to wait in traditional queue areas. All Guests wishing to utilise a Disability Access Service Card should speak with helpful Cast Members in any Disney Theme Park
Guest Relations who will be happy to fully discuss your families particular needs.
Have a great Disney day.
~ Jane