Out of Sate Disabled Parking Placards-Use in Florida???

[SueM in MN]

To be on the safe side though, I would contact the board of tourism in Orlando, and they will probably send you a temporary placard if you are worried.

That won't work.
The handicapped parking permit needs to be issued to the person with a disability in their home state. If they don't need one all the time (or the need is limited - like a broken leg that will heal) they can get a temporary one for a 6 month time period. but, it is issued by their home state, with a form filled out and signed by their doctor.
Most states have information on how to get one (plus usually you can download the form on the state website of the agency that issues them. (In MN, it's the Department of Transportation).

Long ago, WDW used to issue handicapped parking permits for their guests who used wheelchairs. They were only for use on Disney property, but they stopped that when the ADA came into effect. If you have a valid handicapped parking permit for your home state, it will be honored in WDW. One of the points of the ADA was that each state had to honor the handicapped parking permits (hangtags or plates) of other states. Now, as far as I know, the individual states can have differences in exactly what a handicapped permit allows (like some waive parking meter charges, others make you pay; some will allow parking past the posted time, others won't) but for example, Florida can't say they won't honor one from MN.

We have found that most places with valet parking (WDW or elsewhere) will waive the valet charge for someone with a handicapped parking permit.

At least in Minnesota, we can get a handicapped hangtag, but not a handicapped license plate because DD is over 18 and is not the owner or principal driver of our van. If she was, we could still have a handicapped plate, but when we tried to renew after she was 18, we found out we either had to deed the van to her or just have a hangtag.