Volunteering prior to returning to nursing?

I have been out of nursing for over 6 years due to disability. I would love to return to my nursing career but have some concerns about my physical ability to do so, even on a part time or per diem basis. (I would also have to take a refresher course in order to re activate my RN lisence.) I think perhaps volunteering (hospital, hospice, etc.) might give me some insight into whether or not I would be able to handle the physical demands of working again but have concerns about doing so. I was wondering if any other nurses had worked as volunteers and what the experience was like for them. I would appreciate any/all input. Thanks.