My 5 year old son has an ADHD/ASD diagnosis and he has numerous senosory issues as well. We had a wonderful trip to Disney last summer and here are the tips I can recommend:
1) As others have said be sure to get a GAC. The guest relations person I spoke with was so helpful. We had a touring plan but still made use of it mainley for the wheel chair sticker for the stroller. Numerous times he just needed that extra space and the tag saved a few meltdowns I am sure.
2) Noise cancelling headphones.. a huge help. We got the peltor kids ear muffs ones and they worked great and are about 15.00 so they don't break the pocketbook. I believe I ordered ours from
Amazon.
3) Take breaks.. we did lots of swim breaks especially since the water tends to have a calming affect for my son. We also do 1 park day and then do a "rest" day, never two park days in a row.. now if you have limited time this might not be possible.
4) As another poster said lots of snacks, heavy backpack, pushing the stroller, and we also stopped at just about every play area in the park for running/climbin time ie: at hollwood studios the honey I shrunk the kids play area.
5) Watch before you go. I think another thing that really helped was having him watch the rides/shows on
youtube before we left home. Surprises do not go over well and he wathced the rides/shows we planned to do many times before we left home.
6) skip shows with loud sounds or too many effects.
7) plan an exit strategy for shows just in case. We always tried to sit at the end of a row and always paid attention to exits, etc. We never had to use one, but hey you never know!
8) Since your kids are younger.. you may also want to take advantage of the child care centers that offer a nice place just to get out of the sun and not have so much stimulation!
Good luck.. we had a great trip and I am sure you wil too!
Barbara
