Can an adult use a non electric, manual, or "kick" scooter to get to and from shul on shabbat, he never uses it otherwise. In the summer in FL it is over 90 degrees and a long walk leaves one drenched and walking into AC. Very unpleasant. Scooter would reduce this discomfort.

Shalom, Thank you for your question. First of all a huge “yeshacoach!” (“well done!”) for making all that effort to get to shule in such heat. (I’m sure suffering the heat and humidity there exempts you from any suffering in heat of Gehenom (hell) in the world to come!). As to the question of using a manuel scooter on Shabat to travel to shule . The first thing is that ideally one should turn to the local Rabbi with such a question. In issues of this nature there is a large element of communal policy, above and beyond strict halachic ruling. So, anything I answer here is conditional on the approval of the local Rabbi. The question of using scooters is similar, in some respects, to that of riding a bicycle – and is possibly even less problematic in that there is almost no chance that it will need repairing on Shabbat (something that is one the issues with a bicycle; that it might get a puncture, or the chain need repairing). So, what are the issues? Firstly, if there is no eruv then it is forbidden to ride the scooter outside as it would involve a form of “carrying” or transferring. So, the whole question only applies within an eruv. Next, there is a question as whether it should be forbidden due to the possibility that one may (inadvertently) ride out of the eruv. Additionally, some Rabbis understand that the obligation to walk slower on Shabat than on the weekday includes forbidding riding. The Talmud for example forbids being carried in a sedan chair on Shabat for this reason. Also, some Rabbis believe that the Shabbat should be a day of rest – and the concept of “resting” includes not “bouncing around” but physically sitting or walking etc, but not having the body shake up and down. But the major reason most Rabbis forbid it is the general law that forbids “weekday activities”. While this is a rather loose category to define, bicycle riding would seem to be including in it. Thus, a standard ruling about scooter would be to differentiate between riding for fun (as young children do, up and down the driveway), and riding as a form of transport (which is what you asked about). Transport is certainly a “weekday activity,” and thus forbidden. However, I again recommend you turn to the local Rabbi for his advice and ruling. (On a very practical level he might be able to arrange for you to leave a change of underclothes at shule to change into). Again, may the merit of keeping Shabat be a blessing for you.