I would highly suggest renting a wheelchair or
ECV from an offsite rental location. CSR is huge and you're going to want it to get around the resort. An ECV will give you more freedom. I have heat/sun tolerance issues similar to those than happen with lupus and one thing that does actually help is conserving my overall energy by using a mobility aid. It will also just help keep you from overdoing things in general in terms of your energy/pain levels. You do not need a
DAS if the wheelchair/ECV does provide all the help you need (I realize it probably doesn't, but wanted to make sure you were aware of that). Most queues are mainstreamed so you'll wait with everyone else as normal if all you use is a mobility aid. I'd suggest searching the board for prior posts about traveling with sun & heat sensitivity. You certainly could request a DAS so you could wait in a location that is indoors & air conditioned for those queues that are partially outside, but you need to be able to explain your need for it in terms that have nothing to do with your mobility/stamina. Most queues are shaded and most of the heat/sun will be walking between attractions, but it's definitely worth trying to avoid Other things to do are to plan, as much as possible, to avoid the hottest parts of the day. Making rope drop, taking a break at the hotel for the hottest parts of the afternoon, and then coming back in the evening are going to be some of the most helpful things for you. (I am assuming the September was something non-negotiable, however, in the future you might want to consider going later into the fall or in the winter. September in FL is still generally hot enough that it's a month I won't even consider a trip.) It's also worth looking into frog togs or another cooling device to have.