Volunteering

So I am no taking classes this semester for the pre-reqs i need, financial aid issue messed me up. So i wanted to max out some volunteer hours, whilei have the extra time. Was looking at some apps from hospitals and trying to decide what areas of interest to choose. My eventual goal is to be psychiatrist. So trying to decide in regards to volunteering does certain areas of the hospital stand out or are better on your med school app? I also plan on at least 3 hospitals/areas in this area, peds for awhile, geriatric and general population. Any advice would be helpful. TIA