How to rent a wheelchair at WDW?

I think one of our party might need wheelchair for our longer WDW days this week because of severe foot pain from walking around Universal (long term issue that seems to suddenly be worse).This need happened suddenly so I’m unprepared. Do you rent one as you enter the parks? Do they sell out? We’re at CL 10 all week.

They are available at the front of each park on a first come first serve basis. They are $12 daily or $10 daily if you lock in several days at once. There are usually courtesy chairs in the bus stop area that you can use to get to the entrance and vice versa when leaving. We were there on very low crowd days so availability was never an issue but even then the chairs in the bus area were hit or miss. I’m not sure how it may be with heavy crowds.